2.7" Red-Brown Jarosite Crystals on Barite - Colorado Mine, Utah

Jarosite is the most common mineral of the alunite supergroup with a base chemical formula of KFe3+ 3(SO4)2(OH)6. The crystals are usually found as brown to amber-yellow granular crusts or coatings within cavities. The crystals are often very small: larger crystal formations are considered relatively rare. The crystals are most often found with tabular and/or pseudo-cubic structures.

Barite, commonly spelled baryte, is well-known for its great range of colors and varied crystal forms and habits. = It is a heavy mineral consisting of barium sulfate, and typically has the chemical formula of BaSO4. The barite group consists of baryte, celestine, anglesite, and anhydrite. It is generally white to colorless and is the main source of barium.