Interesting Sphalerite Crystal
Interesting Sphalerite Crystal. Photo Credit: Lászlo Tóth

Sphalerite (sometimes spelled sphaelerite) is a sulfide mineral with the chemical formula (Zn,Fe)S.  It is the most important ore of zinc. Sphalerite is found in a variety of deposit types, but it is primarily in sedimentary exhalative, Mississippi-Valley type, and volcanogenic massive sulfide deposits. It is found in association with galena, chalcopyrite, pyrite (and other sulfides), calcite, dolomite, quartz, rhodochrosite, and fluorite.

Formula: (Zn,Fe)S
System: Isometric
Colour: Yellow, light to dark ...
Lustre: Adamantine, Resinous
Hardness: 3½ - 4

From: Pit aid (Halsbrücke, Germany).