Sulfur
Image: AlexmarPhoto (CC BY 4.0)
Mineral NameSulfur
Chemical FormulaS
Mohs Hardness1.5
Crystal Systemorthorhombic
Lusterresinous
Streak Colorwhite to pale yellow
Cleavagepoor/indistinct on {001} and {110}
Fractureconchoidal
Specific Gravity2.07
Colorsyellow, lemon-yellow, brownish-yellow, greenish-yellow, orange-yellow
Transparencytransparent to translucent
Type LocalitySicily, Italy
Mineral GroupNative Elements
Usesindustrial, chemical, fertilizers, fungicides, pharmaceuticals
Associated Mineralsgypsum, calcite, aragonite, celestine
Raritycommon
Description
This microscopic image shows intricate, feather-like or dendritic crystal growths of sulfur, displaying vibrant iridescent colors (yellow, orange, blue, black) due to polarized light. The patterns are characteristic of rapid crystallization from a melt.
Geological Context
Sulfur forms in volcanic fumaroles, hot springs, and sedimentary evaporite deposits, often as a result of bacterial reduction of sulfates or oxidation of hydrogen sulfide. It can also occur in salt domes and as a byproduct of sulfide mineral alteration.
