I've found numerous rocks with dull black crystals in and around Silver Spring, MD. Most of the rocks are weathered mica schist (some with garnet as well as the black mineral), some are white quartz. The black crystals are long and thin but too deformed to get a good cross-section. When I try to test relative hardness the black mineral splinters before it scratches. I've been told the crystals are tourmaline, but according to what info I've found, tourmaline does not occur in this area. Any thoughts on what the black mineral might be? I didn't post photos because I can't get a good enough picture to be useful.

From Adelaide - June 26, 2009 at 10:04:34
Email: Adelaide[ ]ix.netcom.com

Message: 67987