Everyone knows there's money in oil. But can you imagine if an oil painting you got as a housewarming gift 40-odd years go turned out to be worth $500,000?

That's the value that "Antiques Roadshow" put on a Clyfford Still painting hanging on a California couple's wall since the 1960s. The amazing find is featured on the first episode of the show's 12th season, slated to air in January 2009.

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"Clearly, the woman who brought this to us knew she had something special," executive producer Marcia Bemko told the New York Post. "She just didn't know how special it was."

The $500,000 price tag makes the painting the most valuable object appraised in the PBS program's history. And it may sell for much higher. A Clyfford Still recently sold at auction for $21 million, the appraier Alasdair Nichol tells the woman on the 'Antiques' episode, "so, in fact, it may turn out that I'm being rather conservative when I say half a million."

Go the NYPost.com for the full report.