Mining in New England and surrounding area

Hi,

I will be visiting Boston in late May-early June. During my visit, I
would like to do some mining. In addition to Herkimer diamonds, are
there any good mines that allow visitors to mine/pan for a fee? I was
looking at the Maine mine for tourmalines, but visitors we spoke to
were disappointed.

I have no particular gemstones in mind, so any suggestions are
welcome!

Thanx and keep shining,
Devora