David Williams , CNN Written by

A previously unknown drawing by Egon Schiele turned up in a Habitat for Humanity thrift store in Queens, New York, more than 100 years after the Austrian painter's death -- and it could sell for more than $100,000.

Schiele made the pencil drawing of a reclining nude girl in 1918, the year he died of Spanish flu, said Jane Kallir, director of Galerie St. Etienne in New York, who published the first complete catalog of Schiele's watercolors and drawings in 1990.

Schiele was part of Austria's expressionist movement and was mentored by Gustav Klimt.

Kallir said a man contacted her last year after buying the drawing at the thrift shop, but the photos were too blurry for her to tell much about it.

That happens all the time, she said. "We get hundreds of photographs a year, and most of them are fakes or copies or just misidentified as Schiele's work. We asked for better photos, and he took a year to get back to us."

The next set of photos was better, and she asked the man to bring the drawing to the gallery.

She wouldn't identify the man because he wants to remain anonymous.

Kallir said that when she saw the piece in person, she was 99% sure that it was the real thing, but she took some time to compare it the Schiele's other work.

"I wanted to see how this drawing fit with the other drawings," she said. "It fit perfectly, and I could almost pinpoint the modeling session from which it came, so then my initial gut was confirmed, and I said 'yeah, this is it.' "

Schiele did about 20 drawings of this girl and her mother, and Kallir said two were probably made on the same day as this drawing. Those works are now in the collections of the Metropolitan Museum of Art and the Leopold Museum in Vienna, Austria.

The drawing is now for sale in her gallery and on display as part of an exhibit called " The Art Dealer as Scholar ."

If it sells, the man who found the drawing plans to donate some of the proceeds to Habitat for Humanity New York City, Kallir said.

"We are ecstatic!" Karen Haycox, chief executive of Habitat for Humanity New York City, told The Art Newspaper . "And, maybe a little bit in shock but ultimately really happy for all involved.

"I can't help but think that were it not for the Habitat NYC ReStore , this piece of art history might have ended up in a landfill, lost forever."

'Like a piece of junk'

Kallir says that TV programs like "Antiques Roadshow" and "American Pickers" give the impression that "there are treasures in every junk shop and every attic and every basement."

That's not been her experience. "I've been doing this since the 1980s, and this is only the second time something like this has happened," she said.

She says the man who found the drawing is a part-time art handler, picker and collector who has a good eye and got really lucky.

Schiele's work wasn't particularly valuable until the 1970s, and Kallir said this drawng was put in a frame in the '60s. At some point, the date and his signature were cut off.

"You're looking at something that, at that moment, wasn't worth all that much, that was framed in a manner that made it look like a piece of junk, so somebody gave it away without knowing what they had," she said.

National treasure in Austria

Kallir said that a lot of Schiele's work was brought to America by Jews and other Europeans fleeing the Nazis in the late 1930s and '40s, and more came in after World War II.

But Schiele was virtually unknown in the United States, she said.

"In Austria, where my grandfather had his first gallery, Egon Schiele is like a national treasure," she said. "He's one of the most famous artists of the modern period in Austria."

Her grandfather started Galerie St. Etienne in 1939 after coming to New York as a refugee.

"He devoted his entire life to studying this artist and making him better known, and when he passed away in 1978, I simply continued the tradition," Kallir said.