Not a rare date, but an interesting story and a beautiful coin... I had posted some coin pictures on Facebook and an old friend I hadn't seen in a while asked me "How much is a 1919 dime worth?" I gave the standard response "Well, it depends if it has a mint-mark and the condition. It's not a rare date, so if it's worn out, it's only worth the silver content, but it can be worth more in nice condition."
"Well, the holder says 1919-P XF." I told her that it's worth about 10 bucks or so retail, though she wouldn't be able to get anything near that from a dealer. As it happened, I needed one, so she was happy to sell it to me. Apparently somebody had given it to her father as a gift because he was born in 1919 and she had just found it while going through some his stuff. He's been dead at least 20 years, and who knows how long before then he got it - it's been in a box in a closet, forgotten about for decades. He wasn't a collector so it was the only coin there.
She met me at a Farmer's market, and when she handed me the coin, it looked like a slice of opal in the sun. Under diffuse light, it's shades of gray and taupe, darker toward the rim, with a splash of orange on the back. But when it hits the light right, it's the most iridescent coin I've ever seen.

