While we have truffle like mushrooms around here related to boletes, I have not seen any true truffles before. If you have any, or a piece of one, I will be seeing a professional mycologist on sunday and would be happy to get a positive ID on it.
I am located in Mirror Lake, am I correct to assume you are in the 20 mile bay area? I am very interested in seeing what you have found- no I do not intend to hunt for them, but it would be an excellent find if it really is a black truffle.
You can call me any time at 651-7509, I hope you have even a tiny piece of it left!
My finds today were a 5lb maitake and a few matsutake