1) Copper mineral 2) Trigonal mineral
Found on
https://www.crosswordclues.com/clue/geerite
Geerite is a copper sulfide mineral with the chemical formula Cu8S5. The mineral is named after the original collector, Adam Geer, of Utica, New York, USA. ==Crystallography== Geerite is in the crystal class {overline|3}. This means that the crystal could be inverted and then rotated by 120 degrees to return to its original position. The optical c...
Found on
http://en.wikipedia.org/wiki/Geerite
No exact match found.
