3.6" Sphalerite and Dolomite Association - Canada
This specimen contains dolomite and sphalerite crystals, and was collected from the Pine Point Mine in Canada. The white dolomite stands out between the sphalerite crystals clusters that coat what could be considered the top of the specimen. Galena can also be found within the matrix.
Sphalerite is a part of the sulfides group and typically exhibits a grey/black appearance due to high concentrations of impurities. When sphalerite is in it's purest state, the chemical composition is ZnS, and can display a gemmy transparent light tan/yellow color. This is one of the few minerals that can form crystals ranging anywhere between gemmy and transparent to opaque and metallic-like. Opaque or cloudy sphalerite tends to be most abundant, due to the ease of iron replacing zinc in the process of formation.
Galena is a lead based mineral that is in fact the primary ore of lead, and has been used for its lead content for thousands of years. Galena typically displays a gray metallic luster and forms cubes or octahedral crystals. The chemical composition of galena is PbS.