(WLIO) -- There was an exciting discovery recently at Indiana's Evansville Museum.
A painting had been misidentified as a stained glass piece and kept in storage for 50 years turned out to be something much more valuable: an original Picasso.
The museum says the Picasso is too valuable to be put on display and will be sold privately.
Those at the Evansville Museum are pretty good at keeping a secret.
They've known about the Picasso since February, but just made a final decision about what to do with it.
30,000 works of art are at the museum, and many spend time in storage.
The Picasso wouldn't have been there so long if the museum would have known it was a Picasso to begin with.
"I'm telling you, when this thing lights up, it's just, it's unbelievable," said museum director John Streetman.
That's how Streetman describes the hidden treasure, a piece titled "Seated Woman with Red Hat".
The piece of art is not a painting or drawing, but intead a 'Gemmaux,' made by baking different pieces of colored glass.
It's that word Gemmaux that disguised the work's true value all this time.
"When the piece came in, the documents associated with the gift indicated it was by an artist named 'Gemmaux', and it was from a design inspired by a Picasso oil painting," said museum curator Mary Bower.
It wasn't until this past February, when a New York auction house called with questions about the piece, that Bower and others found out it wasn't just inspired by Picasso, it was created by him.
"Good news. It's really, really good news," said trustee president Steven Crohn.
"In the history of our museum, this is the most important moment," Streetman said. "This is the biggest thing that's happened to the museum or probably will happen to the museum. It's enormous."
Enormous is also a way to describe the price tag that museum officials say would come with keeping the art safe it if was put on display.
"The value of the piece makes it prohibitive for us to insure it. Then we would have all sorts of considerations about staffing all sorts of electronic additions, to what we do with our facility that just makes it impossible to keep, and we're so sad about that," Streeman said.
So, after months of meetings, "Seated Woman with Red Hat" is headed to New York to be privately sold, quite possibly for millions.