That's a circulated 1966 dime minted in Philadelphia (that's why there's no mint mark). Clad coins like these can darken if they spend time outside or buried in the ground. Nothing special, worth 10 cents. It's usually best to start a new thread to discuss a new coin, and one good picture of the front and back are all that's needed. Welcome to the site.
I recently had a 1969-D RB no FG Lincoln cent graded by PCGS. I must have put it in the album when I was a teenager because it graded MS64. According to PCGS its value is $200.00. Hope that helps a bit.