Is any of that junk in your attic worth some money? How do you sort the trash from the treasure? CBS News Saturday Morning continues its series with collectibles expert Tony Hyman with a look at National Geographic magazine.

Hyman is often asked whether oldmagazines have any value. His short answer is,

Find the terra-cotta colored number 1 or others from the 1880s and you'll put $4,000 or more in your pocket. Later, but still very old, "red-cover" issues also have substantial value.

National Geographic dealers will pay at least $200 for issues published before 1905. But after that, the value drops dramatically.

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The reason, Hyman says, is that the number of subscriptions soared in that year due to the "scholarly" interest generated when the magazine added color photos of bare-breasted women from other cultures.

So many copies of the yellow-bordered issues dated after 1915 are still around that they bring very little from collectors. Issues from the 1960s or later bring nothing at all. Books and maps dated after 1930 also have little or no interest to collectors.

Condition is important. Missing pictures, wormholes and mold are the kiss of death in the world of second-hand magazines.

The National Geographic site on the Internet has a special section to help collectors. There is a Dealers Directory that can be used to locate those hard-to-find items and a Collectors' Bulletin Board to exchange information with other National Geographic collectors. The site also features a Collectible of the Month and preservation tips about proper storage and handling of your magazine collection.

According to National Geographic, the journal began publishing in 1888 and "serious collectors prize most highly the magazines from the first twenty-five years of the Society's history. There are many special issues which are highly regarded as well."

Go to Tony Hyman's Web site for more information on collectibles.

Go to the archive of Saturday Morning segments with collectibles expert Tony Hyman.

If you think you have a collectible worth a lot of cash, send an email to: "sat@cbsnews.com." Put "What's it Worth?" in the subject line, or write to: "What's it Worth?", 514 West 57th Street, 6th floor, New York, New York 10019.

Please note that because of the volume of mail received, Saturday Morning can't respond to all requests, but some will be selected and featured on the show in the near future.

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