Chemically,
2H20 + S ---- 2H2S +02
The additional oxygen molecule often proceeds to react to form carbon dioxide. The water that runs off is then considered acid mine drainage. This region has a huge problem with this, and there are some mines designated as superfund sites that need to be cleaned up. One attempt to remedy this has been to put bags of limestone below the tailings piles, so that it will hopefully absorb the acid before it reaches the stream.
My mineralogy teacher, Joe Smyth, took us on a field trip up left hand canyon, and showed us some pegmatites, high grade metamorphic rocks, and then this fluorite mine. The few minutes we spent there wasn't enough for me, I have been back a few times exploring the area. The fluorite there is a pretty purple, but doesn't occur in very solid crystals. The mine was originally a gold mine, but later was further developed for its fluorite.
The main pit. Fractures and fisures have been stained black by manganese bearing waters. |
Looking down at the side shaft. Pick axe for scale, ~3.5 ft long. |
Quartz crystals in matrix. |
Some purple fluorite can be found in the walls and floor of the pit. It is quite rotted and is often found as a purple powder. Crystals here are rare, but I have found weathered cubes in some of the bigger boulders on the floor of the mine. Fluorite has a cubic crystal habit, and can form octahedrons, cubes, and plenty of like variations. On this trip, I wasn't looking for fluorite. I visited some outcrops above the mine and found some quartz crystals exposed from weathering on some fissures. They are a grey color, and embedded in matrix. I managed to chip away a crystal or two.
Two small, loose crystals. |