What is the value of a gold US dime?

Probably 10 cents. It's not real. What you have is either:

> plated as part of a piece of jewelry or as a souvenir

> discolored due to exposure to heat or some chemical

If it's actually gold plated, the plating is probably so thin the labor to separate it would cost more than the value of the gold recovered.

If you think about it for, oh, a second or two, even the most boneheaded government bureaucrat wouldn't authorize the minting of a coin worth maybe 100 bucks and put it in circulation for ten cents.... Or if they made it with just 10 cents worth of gold it would be so tiny you'd need tweezers to pick it up!

The only good news would be if it was from 1964 or earlier. The underlying silver would be worth around $4 in that case.