eye Title Creator

GeoDIL Images 103 103 GeoDIL 2384 by Darla Sondrol image eye 103 favorite 1 comment 0

Turquoise Description: Turquoise, CuAl 6 (PO 4 ) 4 (OH) 8 *5(H 2 O) (hydrated copper aluminum phosphate), is a valuable mineral and is possibly the most valuable, non-transparent mineral in the jewelry trade. Its history also includes beautiful ornamental creations by Native Americans and Persians. Turquoise is often imitated by “fakes”, such as the mineral chrysocolla, and poorer turquoise specimens are often dyed or color stabilized with coatings of various resins. Location: USA ▹ New...

Topics: geology, mineralogy



GeoDIL Images 78 78 GeoDIL 1026 by Darla Sondrol image eye 78 favorite 2 comment 0

Ruby (corundum) from Mysore, India Description: Ruby is the red gemmy variety of corundum, Al 2 O 3 , one of the hardest minerals known. Gem corundum of any other color is called sapphire (although we generally think of sapphire as being blue). The red color in ruby is caused by trace amounts of chromium. The best shade of red for ruby is often given the name “pigeon blood red,” but ruby can be any shade of red to almost pink. This crystal is about 7 cm across. Location: USA ▹ India. Near...

Topics: geology, mineralogy



GeoDIL Images 77 77 GeoDIL 2732 by Darla Sondrol image eye 77 favorite 2 comment 0

Aquamarine (beryl) Description: Aquamarine is the blue, blue-green or aqua variety of the mineral beryl (Be 3 A l2 Si 6 O 18 ). Aquamarine is colored by trace amounts of iron in the crystal structure. Some gem aquamarines have been heat treated to produce the popular blue-green colors from less desirable yellow or pale stones. This gem is an emerald cut aquamarine. This gemstone is courtesy of The Jewel Box , Grand Forks, ND. Collection: The Jewel Box Collection of Gemstones. Tech details: 64...

Topics: geology, mineralogy



GeoDIL Images 67 67 GeoDIL 2522 by Darla Sondrol image eye 67 favorite 2 comment 0

Quartz, amethyst Description: Amethyst, a variety of quartz (SiO 2 ) has been found in siliceous volcanics, occurring as macroscopic crystals and drusy coverings inside of agate lined amygdaloidal cavities or vugs, often forming geodes. Amethyst also occurs in quartz veins. The purple color of amethyst is due to small amounts (approximately 40 parts per million) of iron (Fe 4 + ) impurities at specific sites in the crystal structure of quartz. Location: Brazil. Near Minas Gerais. Collection:...

Topics: geology, mineralogy



GeoDIL Images 64 64 GeoDIL 2752 by Darla Sondrol image eye 64 favorite 3 comment 0

Rhodolite garnet Description: Rhodolite is a name sometimes used for red garnets with compositions between almandine (Fe 3 Al 2 Si 3 O 12 ) and pyrope (Mg 3 Al 2 Si 3 O 12 ). The name is derived from the Greek words rhodon and lithos, meaning rose-stone. This gem is an oval cut and is 3.15 carats. Collection: The Jewel Box Collection of Gemstones. Tech details: 104 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. The Geoscience Digital Image Library (GeoDIL)...

Topics: geology, mineralogy



GeoDIL Images 64 64 GeoDIL 632 by Darla Sondrol image eye 64 favorite 2 comment 0

Gypsum (selenite) Description: Clear gypsum is called selenite. These selenite crystals are about 7 cm in longest dimension. Gypsum has composition CaSO 4 •2H 2 O, and is one of the most common evaporite minerals. Location: Chile Collection: University of North Dakota Mineralogy Collection. Tech details: 521 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. The Geoscience Digital Image Library (GeoDIL) is a collection of Earth science images primarily...

Topics: geology, mineralogy



GeoDIL Images 57 57 GeoDIL 709 by Shannon Heinle image eye 57 favorite 1 comment 0

Heliotrope Description: Heliotrope is also known as bloodstone. Bloodstone is a green jasper dotted with bright red “blood” spots of iron oxide. It was treasured in ancient times and long served as the birthstone for March. This attractive chalcedony quartz is known as heliotrope because in ancient times polished stones were described as reflecting the sun. Many myths and powers are associated with bloodstone. Location: India Collection: University of North Dakota Mineralogy Collection...

Topics: geology, mineralogy



GeoDIL Images 55 55 GeoDIL 1429 by Nessa Eull image eye 55 favorite 1 comment 0

Sapphire Description: To most mineralogists, sapphire refers to all varieties of corundum, Al 2 O 3 (aluminum oxide), that are partly to fully transparent and not red. In the gem trade, some people use sapphire to refer only to blue varieties. Location: India. Near Kashmir. Collection: University of North Dakota Mineralogy Collection #451. Tech details: 261 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. The Geoscience Digital Image Library (GeoDIL) is a...

Topics: geology, mineralogy



GeoDIL Images 50 50 GeoDIL 2657 by Joseph Hartman image eye 50 favorite 0 comment 0

UND/NDSU students, GeoDIL librarians and administrators in action Description: UND/NDSU students, GeoDIL librarians and administrators in action. Collecting data for GeoDIL can be a demanding job. Location: USA ▹ Hawaii Tech details: 75 KB. Vista. Cannon EOS Rebel 55mm. The Geoscience Digital Image Library (GeoDIL) is a collection of Earth science images primarily intended as a teaching and learning resource for K-16 educators and students. This project was initiated at the University of...

Topics: geology, mineralogy



GeoDIL Images 42 42 GeoDIL 782 by Shannon Heinle image eye 42 favorite 0 comment 0

Agate Description: Agate is a cryptocrystalline (crystals too small to be seen even by a microscope) variety of quartz. These varieties are divided more by character than by color. These different variatites are often used as semi-precious gemstones and for decorative purposes. Location: USA ▹ Montana Collection: University of North Dakota Mineralogy Collection #1630. Tech details: 478 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. The Geoscience Digital...

Topics: geology, mineralogy



GeoDIL Images 38 38 GeoDIL 2725 by Darla Sondrol image eye 38 favorite 2 comment 0

Diamond Description: Diamond, elemental carbon (C), is the hardest substance found in nature, but few people realize that diamond is four times harder than the next hardest natural mineral, corundum (sapphire and ruby). Diamond's single flaw (perfect cleavage) is far outdistanced by the sum of its positive qualities. It has a broad color range, high refraction, high dispersion or fire, very low reactivity to chemicals, rarity, and extreme hardness and durability. This sample is a oval cut...

Topics: geology, mineralogy



GeoDIL Images 38 38 GeoDIL 637 by Nessa Eull image eye 38 favorite 1 comment 0

Krohnkite Description: Krohnkite is a secondary copper mineral that is found in the oxidized zones of copper ore deposits. It has composition Na 2 Cu(SO 4 ) 2 ·2(H 2 O). The source of this specimen, 8 cm across, is unkown. Collection: University of North Dakota Mineralogy Collection. Tech details: 456 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. The Geoscience Digital Image Library (GeoDIL) is a collection of Earth science images primarily intended as a...

Topics: geology, mineralogy



GeoDIL Images 36 36 GeoDIL 442 by Neil Kadrmas image eye 36 favorite 1 comment 0

Dioptase, CuSiO 2 (OH) 2 Description: Dioptase is a relatively rare mineral, but is well known because many specimens are exceptionally beautiful. It is one of the few minerals that can be as vivid green as emerald. In some literature dioptase is refered to as “emerald copper.” Dioptase has composition CuSiO 2 (OH) 2 and forms in alteration zones of copper deposits. This sample comes from a famous locality at Altyn-Tube, in the Kirghese Steppes, Kazakhstan. Location: Kazakhstan. Near...

Topics: geology, mineralogy



GeoDIL Images 36 36 GeoDIL 2735 by Darla Sondrol image eye 36 favorite 2 comment 0

Fluorite Description: Fluorite, CaF 2 , commonly occurs as transparent crystals in a great variety of colors. Fluorite is not commonly fashioned into gems, since it is not durable enough to maintain a polish with normal jewelry use. This fluorite sample is courtesy of The Jewel Box , Grand Forks, ND. Collection: The Jewel Box Collection of Gemstones. Tech details: 102 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. The Geoscience Digital Image Library...

Topics: geology, mineralogy



GeoDIL Images 34 34 GeoDIL 2726 by Darla Sondrol image eye 34 favorite 1 comment 0

Fancy Yellow Diamond Description: Diamond, elemental carbon (C), is the hardest substance found in nature, diamond is four times harder than the next hardest natural mineral, corundum (sapphire and ruby). Diamond comes from the Greek word “adamas,” meaning “I tame.” The beautiful hues of colored diamonds are caused by the presence and distribution of small amounts of nitrogen (yellow) or boron (blue) within the diamond. This sample is a cushion cut diamond, with the color/clarity rating...

Topics: geology, mineralogy



GeoDIL Images 32 32 GeoDIL 3133 by Dexter Perkins image eye 32 favorite 0 comment 0

Limestone sea arch, south coast, Portugal Description: This photo shows a small sea arch, cut through limestone, near the southernmost point of Portugal. Location: Portugal Tech details: 462 KB. Outcrop. The Geoscience Digital Image Library (GeoDIL) is a collection of Earth science images primarily intended as a teaching and learning resource for K-16 educators and students. This project was initiated at the University of North Dakota (UND) in fall 2000. Dexter Perkins and Joseph Hartman, of...

Topics: geology, mineralogy



GeoDIL Images 32 32 GeoDIL 2533 by Darla Sondrol image eye 32 favorite 1 comment 0

Beryl, var. aquamarine Description: Beryl is a silicate with the chemical formula Be 3 Al 2 (SiO 3 ) 6 . Beryl is not a well known mineral and it comes in many color varieties. The green beryl, emerald and the blue beryl, aquamarine, are the most popular among gem collectors. Some varieties are fluorescent or insoluble in acids. Beryl is a very important economic mineral and the major source of beryllium. Location: Brazil. Near Minas Gerais. Collection: Ward’s Classroom Collection of Gem...

Topics: geology, mineralogy



GeoDIL Images 29 29 GeoDIL 783 by Darla Sondrol image eye 29 favorite 0 comment 0

Rhodochrosite and quartz Description: The pink and orange mineral is rhodochrosite, MnCO 3 . Most of the rest of the material white to gray is quartz. This sample is 6 cm across. Collection: University of North Dakota Mineralogy Collection #1927. Tech details: 871 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. The Geoscience Digital Image Library (GeoDIL) is a collection of Earth science images primarily intended as a teaching and learning resource for K-16...

Topics: geology, mineralogy



GeoDIL Images 29 29 GeoDIL 799 by Darla Sondrol image eye 29 favorite 1 comment 0

Natrochalcite Description: Natrochalite is an emerald green copper mineral from Chuquicamata, Chile. It is a secondary mineral, often forming in veins or crusts associated with copper ores. It has formula NaCu 2 (SO 4 ) 2 (OH,H 2 O) 2 . This specimen is 7.5 cm in longest direction. Location: Chile. Near Chuquicamata. Collection: University of North Dakota Mineralogy Collection #830. Tech details: 743 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. The...

Topics: geology, mineralogy



GeoDIL Images 29 29 GeoDIL 2782 by Joseph Hartman image eye 29 favorite 1 comment 0

UND Hawaii Spring Break 2002 Description: You will find this no where else! Photos of martians Beth Eslinger and Darla Sondrol. The martians are standing on a recent aa flow in Hawaii. Location: USA ▹ Hawaii. Near Kona. Recent aa flows on the way to Kona. Collection: Joseph Hartman C9252. Tech details: 270 KB. Kodachrome, TIFF. The Geoscience Digital Image Library (GeoDIL) is a collection of Earth science images primarily intended as a teaching and learning resource for K-16 educators and...

Topics: geology, mineralogy



GeoDIL Images 28 28 GeoDIL 1223 by Nessa Eull image eye 28 favorite 0 comment 0

Realgar and orpiment from Felsobanya, Hungary Description: Realgar, AsS (arsenic sulfide), is one of only a few sulfides that are non-metallic, opaque or blandly colored. Realgar occurs in hydrothermal veins with valuable metal sulfide ores and its bright red color is distinctive. Orpiment, As 2 S 3 (arsenic sulfide), is a rare mineral that usually forms with realgar. In fact the two minerals are almost always together. The yellow color is special to orpiment and can be confused only with a few...

Topics: geology, mineralogy



GeoDIL Images 28 28 GeoDIL 179 by Darla Sondrol image eye 28 favorite 1 comment 0

Fluorite from Roxbury, Connecticut Description: This cleavage fragment of fluorite, CaF 2 , is about 6.5 cm across. Fluorite typically forms cubic crystals. Many sharp looking fluorite specimens are octahedral, but they are mostly cleavage fragments rather than whole crystals. Location: USA ▹ Connecticut. Near Roxbury. Collection: University of North Dakota Mineralogy Collection. Tech details: 605 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. The...

Topics: geology, mineralogy



GeoDIL Images 27 27 GeoDIL 1 by Darla Sondrol image eye 27 favorite 1 comment 0

Intergrowth of quartz, sphalerite and pyrite from a hydrothermal deposit Description: This sample, 4 cm across, contains conspicuous prismatic quartz crystals, dark (nearly black) sphalerite, and golden pyrite. The specimen comes from a hydrothermal deposit in Huaron, Peru. Location: Peru. Near Huaron. Collection: University of North Dakota Mineralogy Collection. Tech details: 610 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. The Geoscience Digital Image...

Topics: geology, mineralogy



GeoDIL Images 26 26 GeoDIL 784 by Darla Sondrol image eye 26 favorite 0 comment 0

Dolomite crystals on dolomitic mudstone Description: Here we see nicely formed rhombohedral crystals of dolomite, CaMg(CO 3 ) 2 (calcium magnesium carbonate). They crystallized on top of a slab of dolomitic mudstone. Dolomite crystals often have a beautiful pinkish color, pearly luster and unusual crystal habit that includes curved crystal faces. This sample is 14 cm across. Collection: University of North Dakota Mineralogy Collection #629. Tech details: 789 KB. Hand specimen. Fujifilm FinePix...

Topics: geology, mineralogy



GeoDIL Images 23 23 GeoDIL 3132 by Dexter Perkins image eye 23 favorite 0 comment 0

Limestone sea stacks, south coast, Portugal Description: This view shows limestone sea stacks near the southernmost point of Portugal. Location: Portugal. Near Lagos. Tech details: 565 KB. Vista. The Geoscience Digital Image Library (GeoDIL) is a collection of Earth science images primarily intended as a teaching and learning resource for K-16 educators and students. This project was initiated at the University of North Dakota (UND) in fall 2000. Dexter Perkins and Joseph Hartman, of UND's...

Topics: geology, mineralogy



GeoDIL Images 22 22 GeoDIL 3135 by Dexter Perkins image eye 22 favorite 0 comment 0

Waterfall over basalt, Haleakala National Park, Hawaii Description: Haleakala Volcano dominates east Maui. The drive along its south side passes through some beautiful scenery and offers several short hikes. This waterfall is just a few minutes from the road. Here we see moss covered basalt covered by a fine rain and mist of falling water. Location: USA ▹ Hawaii. Haleakala National Park, Maui. Tech details: 654 KB. Outcrop. The Geoscience Digital Image Library (GeoDIL) is a collection of...

Topics: geology, mineralogy



GeoDIL Images 22 22 GeoDIL 3129 by Dexter Perkins image eye 22 favorite 1 comment 0

Mud cracks, Joshua Tree National Park, California Description: This view shows newly formed mud cracks in Joshua Tree National Park, California. Location: USA ▹ California. Near Joshua Tree. Joshua Tree National Park. Tech details: 625 KB. Outcrop. The Geoscience Digital Image Library (GeoDIL) is a collection of Earth science images primarily intended as a teaching and learning resource for K-16 educators and students. This project was initiated at the University of North Dakota (UND) in fall...

Topics: geology, mineralogy



GeoDIL Images 22 22 GeoDIL 3134 by Dexter Perkins image eye 22 favorite 0 comment 0

Gypsum sand dunes in White Sands National Monument Description: This view shows sand dunes, made of wind-deposited gypsum, at White Sands National Monument, New Mexico. Location: USA ▹ New Mexico. Near Alamagordo. White Sands National Monument picnic area. Tech details: 293 KB. Vista. The Geoscience Digital Image Library (GeoDIL) is a collection of Earth science images primarily intended as a teaching and learning resource for K-16 educators and students. This project was initiated at the...

Topics: geology, mineralogy



GeoDIL Images 21 21 GeoDIL 2 by Dexter Perkins image eye 21 favorite 1 comment 0

Comparison of granite (left) and arkose (right) Description: These samples of granite (on left) and arkose (on right) both contain the same minerals: predominately quartz and K-feldspar. Granite is an igneous rock, so the crystals interlock in a mosaic-like pattern. Arkose is a detrital sedimentary rock, so the crystals are piled together like grains of sand. The red color of both is due to iron oxidation. These samples are part of the Petrology teaching collection of the Department of Geology...

Topics: geology, mineralogy



GeoDIL Images 21 21 GeoDIL 2733 by Darla Sondrol image eye 21 favorite 2 comment 0

Rhodolite (pyrope-almandine garnet) Description: Rhodolite is the rasberry pink to wine colored variety of pyrope-almandine garnet, (Mg,Fe) 3 Al 2 Si 3 O 12 . This gem is a fantasy cut rhodolite and is 4.40 carats. Collection: The Jewel Box Collection of Gemstones. Tech details: 106 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. The Geoscience Digital Image Library (GeoDIL) is a collection of Earth science images primarily intended as a teaching and learning...

Topics: geology, mineralogy



GeoDIL Images 20 20 GeoDIL 3119 by Dexter Perkins image eye 20 favorite 0 comment 0

Hot basalt in Hawaii Volcanoes National Park Description: Hawaii Volcanoes National Park has had nearly continuous basaltic eruptions for many years. During the past decade (1995-2005), intrepid hikers have walked out from the Chain of Craters Road to see the hot lava while it is still glowing, and where it (sometimes) enters the ocean. The flow shown here comes from the Puu Oo vent of Kilauea Volcano. The field ov view is about 6 feet across. Location: USA ▹ Hawaii. Near Hilo. Hawaii...

Topics: geology, mineralogy



GeoDIL Images 20 20 GeoDIL 1469 by Joseph Hartman image eye 20 favorite 0 comment 0

Steinacker Reservoir, Carmel Silicified Fossils Description: Steinacker Reservoir, Carmel Silicified Fossils. Location: USA ▹ Utah Collection: Joseph Hartman P02719 vol. 3-121. Tech details: 362 KB. Outcrop. Etkachrome; TIFF Format. The Geoscience Digital Image Library (GeoDIL) is a collection of Earth science images primarily intended as a teaching and learning resource for K-16 educators and students. This project was initiated at the University of North Dakota (UND) in fall 2000. Dexter...

Topics: geology, mineralogy



GeoDIL Images 19 19 GeoDIL 2711 by Darla Sondrol image eye 19 favorite 1 comment 0

Diamond Description: Diamond, elemental carbon (C), is the hardest substance found in nature, but few people realize that diamond is four times harder than the next hardest natural mineral, corundum (sapphire and ruby). Diamond's single flaw (perfect cleavage) is far outdistanced by the sum of its positive qualities. It has a broad color range, high refraction, high dispersion or fire, very low reactivity to chemicals, rarity, and extreme hardness and durability. This sample is ideal cut, with...

Topics: geology, mineralogy



GeoDIL Images 18 18 GeoDIL 2377 by Darla Sondrol image eye 18 favorite 1 comment 0

Chrysocolla Description: Chrysocolla, CuSiO 3 -nH 2 O, (hydrated copper silicate), is a mineraloid, rather than a true mineral. Most of the time it is amorphous, meaning that it does not have a coherent crystalline structure. Chrysocolla is attractive blue-green that provides a unique color to the mineral world. Location: USA ▹ Arizona. Near Miami. Collection: Ward’s Classroom Collection of Gem Minerals #33. Tech details: 407 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF...

Topics: geology, mineralogy



GeoDIL Images 18 18 GeoDIL 788 by Darla Sondrol image eye 18 favorite 0 comment 0

Quartz with dolomite Description: This sample contains white quartz, SiO 2 (silicon dioxide), and brown dolomite, CaMg(CO 3 ) 2 (calcium magnesium carbonate). Both are common minerals. Quartz is often white (or clear), but this hue of brown is a bit uncommon for dolomite. The quartz crystals in this sample have quartz's typical hexagonal prismatic shape. Dolomite typically forms rhombohedrons but some crystals (such as the ones in this specimen) curve into elongate saddle-shaped crystals. This...

Topics: geology, mineralogy



GeoDIL Images 18 18 GeoDIL 439 by Neil Kadrmas image eye 18 favorite 1 comment 0

Amazonite (microcline) Description: Amazonite is a term used to describe green to blue microcline that is sometimes used as a gemstone. More typically, microcline (a K-feldspar) is white to tan in color. In this photo, the “pseudo-hexagonal” nature of the feldspar crystals can be seen. This specimen is 7 cm across. It comes from a well-known collecting site at the Rocket Mining Claim, near Pikes Peak, Colorado. Location: USA ▹ Colorado. Near Colorado Springs. Rocket Mining Claim....

Topics: geology, mineralogy



GeoDIL Images 18 18 GeoDIL 3131 by Dexter Perkins image eye 18 favorite 1 comment 0

Olivine mine on the Apache Indian Reservation at San Carlos, Arizona Description: Olivine, some of it in quite large near gem-quality peridot crystals, is mined from pits on the San Carlos Apache Indian Reservation, Arizona. Those who obtain special permission may get access to the pits and search for themselves. As can be seen in this photo, there is lots of green olivine. Large crystals, however, are sometimes a bit difficult to find because the area has been well picked over. Location: USA...

Topics: geology, mineralogy



GeoDIL Images 18 18 GeoDIL 3125 by Dexter Perkins image eye 18 favorite 0 comment 0

Weathered and eroded granite outcrops, Alabama Hills, near Lone Pine, California Description: The Alabama Hills are an area of weathered and eroded granite outcrops lying between Lone Pine, California, and the Sierra. The granite here is the same age as the Sierra Nevada Batholith. This area has been the backdrop for many Hollywood movies, especially cowboy flics. Location: USA ▹ California. Near Lone Pine. Tech details: 567 KB. Vista. The Geoscience Digital Image Library (GeoDIL) is a...

Topics: geology, mineralogy



GeoDIL Images 17 17 GeoDIL 3126 by Dexter Perkins image eye 17 favorite 0 comment 0

Shield volcanoes: View of Mauna Kea (left distance) and Mauna Loa (right distance) from Maui Description: This is a view from the highest point in Haleakala National Park on Maui, east across the ocean to Hawaii’s big island. The two mountains that can be seen on the big island are Mauna Kea (left) and Mauna Loa (right). Shiled volcanoes are often so large that they are hard to photograph. Fortunately, the Hawaiian islands provide room to step back and get a large view. Location: USA ▹...

Topics: geology, mineralogy



GeoDIL Images 17 17 GeoDIL 2451 by Dexter Perkins image eye 17 favorite 0 comment 0

Puy de Pariou and Puy de Dome, Auvergne, France Description: The Massif Central in the center of France (Auvergne region), contains a range of volcanoes made up of the Monts Dome (1465 meters at the Puy de Dome) and the Monts Dore (1886 meters at the Puy de Sancy). Eruptions included both Peleean (involving the formation and collapse of lava domes) and Strombolian (lava fountains and ejection of cinders, lapilli, blocks and bombs). The last eruptions were about 4,000 years ago. The region...

Topics: geology, mineralogy



GeoDIL Images 17 17 GeoDIL 3124 by Dexter Perkins image eye 17 favorite 0 comment 0

Erosion on the south side of Haleakala, Hawaii Description: Erosion on the south side of Haleakala, Hawaii. Location: USA ▹ Hawaii. Near Hilo. Haleakala National Park. Tech details: 193 KB. Vista. The Geoscience Digital Image Library (GeoDIL) is a collection of Earth science images primarily intended as a teaching and learning resource for K-16 educators and students. This project was initiated at the University of North Dakota (UND) in fall 2000. Dexter Perkins and Joseph Hartman, of UND's...

Topics: geology, mineralogy



GeoDIL Images 17 17 GeoDIL 3130 by Dexter Perkins image eye 17 favorite 0 comment 0

Searching for olivine at San Carlos, Arizona Description: Olivine, some of it in quite large near gem-quality peridot crystals, is mined from pits on the San Carlos Apache Indian Reservation, Arizona. Those who obtain special permission may get access to the pits and search for themselves. As can be seen in this photo, there is lots of green olivine. Large crystals, however, are sometimes a bit difficult to find because the area has been well picked over. Location: USA ▹ Arizona. Near San...

Topics: geology, mineralogy



GeoDIL Images 17 17 GeoDIL 3122 by Dexter Perkins image eye 17 favorite 0 comment 0

Breccia, California coast, Point Lobos State Reserve Description: At Point Lobos, fine exposures reveal turbidites. Thick sequences of sandstones, conglomerates and breccias can be seen. This view shows coarse breccia over a finer grained unit that is mostly mudstone. The field of view is about 8 feet wide. Location: USA ▹ California. Near Big Sur. Point Lobos State Reserve. Tech details: 844 KB. Outcrop. The Geoscience Digital Image Library (GeoDIL) is a collection of Earth science images...

Topics: geology, mineralogy



GeoDIL Images 17 17 GeoDIL 904 by Shannon Heinle image eye 17 favorite 2 comment 0

Aquamarine Description: Aquamarine Be 3 Al 2 Si 6 O 18 is the blue to blue-green or aqua variety of the mineral beryl. Aquamarine is colored by trace amounts of iron that find their way into the crystal structure. The environment that beryl is found in is mostly granitic pegmatites. Gem aquamarines can be heat treated to produce a more desireable color from lesser pale colored stones. Its name comes from the ancient Greek, beryllos, signifying a “precious blue-green color of sea water”...

Topics: geology, mineralogy



GeoDIL Images 16 16 GeoDIL 20 by Dexter Perkins image eye 16 favorite 0 comment 0

Tabular barite with calcite and pyrite, from Joplin, Missouri, USA Description: Large tan barite (BaSO 4 ) tabs, some appearing pseudo-hexagonal, are embedded in finer white calcite, CaCO 3 . Pyrite crystals, FeS 2 , generally about 1 mm across are scattered in the sample. No provenance data is available except that it comes from Joplin, Missouri, USA. This photo is about 5 cm across. Location: USA ▹ Missouri. Near Joplin. Collection: University of North Dakota Mineralogy Collection. Tech...

Topics: geology, mineralogy



GeoDIL Images 16 16 GeoDIL 3128 by Dexter Perkins image eye 16 favorite 0 comment 0

Spinefex texture in ultramafic lava outcrops at Pike Hill, Monroe Township, Ontario Description: Archaean komatiites are exposed in a small hill in Monroe Township, Ontario. This classic locality is sometimes referred to as “Pike Hill”, named after a geologists who did extensive work there. It has, unfortunately, been considerably damaged by geologists with large hammers! The outcrop has many spectacular examples of spinefex textures. Chronostratigraphy: Archean. Location: Canada ▹...

Topics: geology, mineralogy



GeoDIL Images 16 16 GeoDIL 377 by Twyla Baker image eye 16 favorite 1 comment 0

Hedenbergite syenite, Portland Township, Quebec, Canada Description: This syenite is dominated by alkali feldspar but also contain small amounts of plagioclase and quartz. Hedenbergite, Ca-Fe pyroxene, is located in the dark veins. The specimen is 9.5 cm across. Location: Canada ▹ Quebec ▹ Portland Township Collection: Ward’s Collection of Classic North American Rocks #110. Tech details: 974 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. The Geoscience...

Topics: geology, mineralogy



GeoDIL Images 16 16 GeoDIL 1678 by Shannon Heinle image eye 16 favorite 1 comment 0

Serpentine Description: Serpentine is a magnesium iron silicate hydroxide. Serpentine is a major rock forming mineral and is found as a constituent in many metamorphic and weather igneous rocks. It often colors many of these rocks to a green color and most rocks that have a green color probably have serpentine in some amount. Serpentine is a general name applied to several members of a polymorphic group. It has been used as a substitute for jade and is sometimes difficult to distinguish from...

Topics: geology, mineralogy



GeoDIL Images 16 16 GeoDIL 100 by Dexter Perkins image eye 16 favorite 0 comment 0

Navajo Sandstone, Wingate Sandstone, Chinle Formation, and Moenkopi Formation exposed in a cliff, Capitol Reef National Park Description: This photo shows the Moenkopi Formation (red castellated outcrop near bottom of cliff), overlain by the Chinle Formation (grennish to red slope), overlain by the steep Wingate Sandstone cliff. In the far distance, just barely visible is the whitish Navajo Sandstone. All are of Triassic age, although in some parts of Utah the Navajo Sandstone is considered...

Topics: geology, mineralogy



GeoDIL Images 16 16 GeoDIL 1682 by Joseph Hartman image eye 16 favorite 0 comment 0

Modern Corals Description: Modern Corals. Location: USA Collection: Joseph Hartman P02268. Tech details: 206 KB. Kodachrome, TIFF format. The Geoscience Digital Image Library (GeoDIL) is a collection of Earth science images primarily intended as a teaching and learning resource for K-16 educators and students. This project was initiated at the University of North Dakota (UND) in fall 2000. Dexter Perkins and Joseph Hartman, of UND's Department of Geology and Geological Engineering, are the...

Topics: geology, mineralogy



GeoDIL Images 15 15 GeoDIL 2521 by Darla Sondrol image eye 15 favorite 2 comment 0

Rose quartz Description: Rose quartz, SiO 2 (silicon dioxide), is opaque to translucent macrocrystalline quartz of pink to rose-red color. It normally occurs in the cores of large pegmatites as solid masses of rose colored quartz whose individual crystals have poorly formed boundaries. The color of rose quartz is still not completely understood. It has been said to be due to a number of different minor impurities present including titanium, manganese and even colloidal gold. Location:...

Topics: geology, mineralogy



GeoDIL Images 15 15 GeoDIL 3117 by Dexter Perkins image eye 15 favorite 0 comment 0

Hot basalt in Hawaii Volcanoes National Park Description: Hawaii Volcanoes National Park has had nearly continuous basaltic eruptions for many years. During the past decade (1995-2005), intrepid hikers have walked out from the Chain of Craters Road to see the hot lava while it is still glowing, and where it (sometimes) enters the ocean. The flow shown here comes from the Puu Oo vent of Kilauea Volcano. Location: USA ▹ Hawaii. Near Hilo. Hawaii Volcanoes National Park. Tech details: 969 KB....

Topics: geology, mineralogy



GeoDIL Images 15 15 GeoDIL 47 by Shannon Heinle image eye 15 favorite 1 comment 0

Brucite from Texas, Pennsylvania Description: The light yellowish mineral is brucite from Texas, Pennsylvania. Brucite is Mg(OH)2. Location: USA ▹ Pennsylvania ▹ Lancaster. Near Texas. Collection: University of North Dakota Mineralogy Collection #1908. Tech details: 690 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. The Geoscience Digital Image Library (GeoDIL) is a collection of Earth science images primarily intended as a teaching and learning resource...

Topics: geology, mineralogy



GeoDIL Images 15 15 GeoDIL 497 by Nessa Eull image eye 15 favorite 1 comment 0

Clay ironstone nodule, from near Mazon Creek, Illinois, USA Description: This is a nodule (concretion) from Francis Creek Shale of the Carbondale Formation (Pennsylvanian) near Mazon Creek, Illinois. These concretions, which developed through action of groundwater after the shale was deposited, are made of ironstone, and are mineralogically siderite ( FeCO 3 = iron carbonate) with minor clay. These nodules are famous because many of them, when broken, reveal spectacular plant and animal...

Topics: geology, mineralogy



GeoDIL Images 15 15 GeoDIL 813 by Darla Sondrol image eye 15 favorite 1 comment 0

Sphaerocobaltite from Sudbury, Ontario, Canada Description: The pink mineral is sphaerocobaltite, CoCO 3 (cobalt carbonate), also sometimes called (incorrectly) cobaltocalcite and cobaltian-calcite. (The latter two names are more appropriate for referring to calcite that has an appreciable amount of cobalt in its structure as an impurity.) The sometimes deep rose-red to pink color of this mineral can be very attractive and unique. Sometimes sphaerocobaltite can be confused with other pinkinsh...

Topics: geology, mineralogy



GeoDIL Images 15 15 GeoDIL 310 by Shannon Heinle image eye 15 favorite 2 comment 0

Citrine Description: Citrine is the yellow orange variety of quartz (SiO 2 ). It is rare in nature but can often be obtained by heating the purple variaty of quartz, amethyst. Quartz, one of the most abundant minerals on Earth, is found in nearly every geological environment, and has many different varieties. Varieties include citrine, amethyst, rose quartz, milky quartz, smoky quartz and others. Collection: University of North Dakota Mineralogy Collection. Tech details: 456 KB. Hand specimen....

Topics: geology, mineralogy



GeoDIL Images 15 15 GeoDIL 3127 by Dexter Perkins image eye 15 favorite 0 comment 0

Ultramafic lava outcrops at Pike Hill, Monroe Township, Ontario Description: Archaean komatiites are exposed in a small hill in Monroe Township, Ontario. This classic locality is sometimes referred to as “Pike Hill,” named after a geologists who did extensive work there. It has, unfortunately, been considerably damaged by geologists with large hammers! The outcrop has many spectacular examples of spinefex textures. Chronostratigraphy: Archean. Location: Canada ▹ Ontario. Near Noranda....

Topics: geology, mineralogy



GeoDIL Images 14 14 GeoDIL 847 by Shannon Heinle image eye 14 favorite 1 comment 0

Chalcedony Description: Chalcedony is a cyptocrystalline (crystals too small to be seen even by a microscope) variety of quartz. These varieties are divided more by character than by color. Chalcedony or agate is divided into innumeral types that have been named for locally common varieties. Collection: University of North Dakota Mineralogy Collection #1636. Tech details: 188 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. The Geoscience Digital Image Library...

Topics: geology, mineralogy



GeoDIL Images 14 14 GeoDIL 706 by Nessa Eull image eye 14 favorite 1 comment 0

Calcite with quartz and ankerite, Galena, New Mexico Description: This is a geode containing calcite, CaCO 3 , with quartz, SiO 2 , and ankerite, CaFe(CO 3 ) 2 . The ankerite is brown, the calcite is the large white crystals, and the quartz is all in small crystals on the interior wall of the geode. This sample comes from Galena, New Mexico, and is about 6 cm across. Location: USA ▹ New Mexico. Near Galena. Collection: University of North Dakota Mineralogy Collection #642. Tech details: 677...

Topics: geology, mineralogy



GeoDIL Images 14 14 GeoDIL 2166 by Joseph Hartman image eye 14 favorite 0 comment 0

Nashville Description: Nashville, TN. Location: USA ▹ Tennessee. Near Nashville. Collection: Joseph Hartman C8792. Tech details: 403 KB. Outcrop. Ektachrome. The Geoscience Digital Image Library (GeoDIL) is a collection of Earth science images primarily intended as a teaching and learning resource for K-16 educators and students. This project was initiated at the University of North Dakota (UND) in fall 2000. Dexter Perkins and Joseph Hartman, of UND's Department of Geology and Geological...

Topics: geology, mineralogy



GeoDIL Images 14 14 GeoDIL 1375 by Joseph Hartman image eye 14 favorite 0 comment 0

Supai Group sandstones, Grand Canyon National Park, Arizona Description: View of cross bedding and exfoliation of Supai Group in North Canyon off Marble Canyon, Grand Canyon National Park. Chronostratigraphy: Lower Pennsylvanian to Lower Permian. Lithostratigraphy: Supai Group. Geologic province: Colorado Plateau. Location: USA ▹ Arizona ▹ Coconino. Near Grand Canyon. Grand Canyon National Park. Collection: Joseph Hartman P06105. Tech details: 751 KB. Outcrop. Kodachrome, TIFF format. The...

Topics: geology, mineralogy



GeoDIL Images 14 14 GeoDIL 16 by Dexter Perkins image eye 14 favorite 0 comment 0

Garnet-wollastonite skarn, Willsboro, NY, USA Description: This sample is about 10 cm across. It is a metamorphic rock formed by contact metamorphism of Grenville-aged (Precambrian) limestone. Macroscopic minerals are white, coarse wollastonite, dark brown-red andraditic garnet and speckles of light green diopside. This sample comes from the eastern side of the Adirondack Mountains, New York. Chronostratigraphy: Precambrian. Geologic province: Grenville. Location: USA ▹ New York ▹ Essex....

Topics: geology, mineralogy



GeoDIL Images 14 14 GeoDIL 3 by Dexter Perkins image eye 14 favorite 1 comment 0

A large pyrite crystal with smaller quartz crystals on top Description: This sample contains a large pyrite crystal (about 6 cm across) with smaller quartz prisms on top. It is from a hydrothermal ore deposit near Climax, Colorado. Note the growth striations that can be seen on the surface of the pyrite crystal. Location: USA ▹ Colorado. Near Climax. Collection: University of North Dakota Mineralogy Collection. Tech details: 100 KB. Hand specimen. Provia E6 film, Canon A1 with macro lens,...

Topics: geology, mineralogy



GeoDIL Images 14 14 GeoDIL 613 by Darla Sondrol image eye 14 favorite 1 comment 0

Gypsum crystal with swallowtail twin Description: Gypsum crystals often interpentrate to form what is called a “swallowtail twin.” The vertical crystal shown here is actually composed of two different crystal domains that share common atoms. The top surface has a reentrant angle because of the two different domains. This specimen is 9 cm tall. Collection: University of North Dakota Mineralogy Collection #790. Tech details: 334 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm...

Topics: geology, mineralogy



GeoDIL Images 14 14 GeoDIL 3116 by Dexter Perkins image eye 14 favorite 0 comment 0

Hot basalt in Hawaii Volcanoes National Park Description: Hawaii Volcanoes National Park has had nearly continuous basaltic eruptions for many years. During the past decade (1995-2005), intrepid hikers have walked out from the Chain of Craters Road to see the hot lava while it is still glowing, and where it (sometimes) enters the ocean. The flow shown here comes from the Puu Oo vent of Kilauea Volcano. Location: USA ▹ Hawaii. Near Hilo. Hawaii Volcanoes National Park. Tech details: 774 KB....

Topics: geology, mineralogy



GeoDIL Images 14 14 GeoDIL 902 by Dexter Perkins image eye 14 favorite 0 comment 0

Botryoidal smithsonite Description: This sample of smithsonite comes from an unknown location in Montana. It precipitated from water, giving it the botryoidal (grape like) appearance you see here. Smithsonite, ZnCO 3 , is a minor zinc ore mineral. There are few other minerals that can have this green color or habit; prehnite is the only relatively common one. Collection: University of North Dakota Mineralogy Collection #717. Tech details: 624 KB. Hand specimen. Fujifilm FinePix S1Pro digital...

Topics: geology, mineralogy



GeoDIL Images 14 14 GeoDIL 312 by Dexter Perkins image eye 14 favorite 1 comment 0

Petroglyph on basalt in Albquerque, New Mexico Description: Petroglyph National Monument is really an urban park, stretching about 15 miles along the west side of Albuquerque, New Mexico. It is famous for its impressive collection of ancient Indian and Hispanic rock art on weathered brown basalt. In some places the rock art is mixed with modern graffiti. Location: USA ▹ New Mexico. Near Albuquerque. Collection: E41111991V. Tech details: 391 KB. Outcrop. The Geoscience Digital Image Library...

Topics: geology, mineralogy



GeoDIL Images 14 14 GeoDIL 2750 by Darla Sondrol image eye 14 favorite 0 comment 0

Tourmaline Description: Tourmaline's name comes from the Sinhalese word “turmali,” which means “mixed.” Tourmaline occurs in more colors and combinations of colors than any other gemstone variety, and there is a tourmaline that looks like almost any other gemstone. This gemstone is a pink tourmaline with a fancy square cut and is 1.14 carats. This gem is courtesy of The Jewel Box , Grand Forks, ND. Collection: The Jewel Box Collection of Gemstones. Tech details: 117 KB. Hand specimen....

Topics: geology, mineralogy



GeoDIL Images 14 14 GeoDIL 620 by Darla Sondrol image eye 14 favorite 1 comment 0

Gypsum (selenite), CaSO 4 •2H 2 O Description: Gypsum has many different appearances. Most commonly it is massive and opaque. Clear samples, like this one are called selenite. This specimen is 8 cm across. Collection: University of North Dakota Mineralogy Collection #797. Tech details: 1016 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. The Geoscience Digital Image Library (GeoDIL) is a collection of Earth science images primarily intended as a teaching...

Topics: geology, mineralogy



GeoDIL Images 14 14 GeoDIL 2466 by Darla Sondrol image eye 14 favorite 0 comment 0

Quartz, jasperized wood (tumbled) Description: Jasperized wood (xyloid jasper) is petrified wood. It is wood that has fossilized - all the original chemicals have been replaced with minerals, making a stone-like replica of the original wood. Location: USA ▹ Arizona. Near Holbrook. Collection: Wards Classroom Collection of Gem Minerals #20. Tech details: 146 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera; 60mm AF Nikon micro lens. The Geoscience Digital Image Library (GeoDIL) is a...

Topics: geology, mineralogy



GeoDIL Images 14 14 GeoDIL 1548 by Shannon Heinle image eye 14 favorite 1 comment 0

Hedenbergite Description: This sample is about 4 cm. The chemical formula for hedenbergite is CaFeSi 2 O 6 . Hedenbergite is a rock forming mineral in several metamorphic rocks. It is also found in some igneous rocks and ore bodies. Hedenbergite is a cousin to diopside. The mineral is named after the Swedish mineralogist, M. A. L. Hedenberg. Collection: University of North Dakota Mineralogy Collection #4007. Tech details: 735 KB. Hand specimen. Fujifilm FinePix S1Pro digital camera. The...

Topics: geology, mineralogy



GeoDIL Images 14 14 GeoDIL 2398 by Dexter Perkins image eye 14 favorite 0 comment 0

Rock Climber on exfoliation slab (Wheat Thin), Yosemite Valley, California Description: The granitic rocks exposed the Yosemite Valley area are part of the Sierra Nevada batholith (from the Greek words bathos, deep, and lithos, rock). The batholith consists of plutons of Cretaceous age that intruded over about a 30 million year period. The rocks are generally called granitic because they are principally composed of K-feldspar, quartz and plagioclase. The ratios of these three minerals are...

Topics: geology, mineralogy



GeoDIL Images 14 14 GeoDIL 2737 by Darla Sondrol image eye 14 favorite 0 comment 0

Opal Description: Opal, SiO 2 -nH 2 O (hydrated silicon dioxide), is considered a mineraloid because its structure is not truly crystalline. The chemistry of opal is primarily SiO 2 and varying amounts of water from 5%-10% and greater. This water can help geologists determine the temperature of the host rock at the time the opal formed. The gem in this photo is courtesy of: The Jewel Box , Grand Forks, ND. Collection: The Jewel Box Collection of Gemstones. Tech details: 38 KB. Hand specimen....

Topics: geology, mineralogy



GeoDIL Images 14 14 GeoDIL 865 by Dexter Perkins image eye 14 favorite 0 comment 0

Malachite Description: This 10 cm tall sample, from an unknown location, contains conspicuous turquoise-blue malachite, Cu 2 (CO 3 )(OH) 2 , with yellow-brown and red-brown limonite (a rusty mix of various iron hydroxides and oxides). Clear calcite crystals, CaCO 3 , have grown into some of the open spaces. Malachite is a pretty mineral, and some specimens are semi-precious gemstones. It often precipitates in vugs forming layers of different colors, as in this photograph. Individual crystals...

Topics: geology, mineralogy



GeoDIL Images 14 14 GeoDIL 3121 by Dexter Perkins image eye 14 favorite 0 comment 0