Mineral specimen of Dolomite Chalcopyrite and Quartz. Great contrast of colours with the white Dolomite and sparkling Chalcopyrite with Quartz on a grey host matrix.
Sweetwater Mine, Ozark Lead Company, Ellington, Missouri, USA.
6.8cm x 3.7cm x 4.2cm, 98g.
Calcium Magnesium Carbonate: CaMg(CO3)2.
Dolomite named for the French mineralogist Deodat de Dolomieu. A common sedimentary rock forming mineral that can be found in massive beds several hundred feet thick. Dolomite rock is one of the sedimentary rocks that undergoes a significant mineralogical change once deposited. Deposited as Calcite Aragonite rich limestones. During a process called diagenesis the Calcite Aragonite is altered to Dolomite. The process is not metamorphism but something just short of that. Magnesium rich ground waters with a significant amount of salinity are crucial and warm tropical near ocean environments are probably the best source of dolomite formation.
Named in 1725 by Johann Friedrich Henckel from the Greek “chalkos”, copper, and “pyrites”, strike fire.
A major ore of copper. Common in sulfide veins and disseminated in igneous rocks. Weathering may lead to the formation of malachite, azurite, brochantite, langite and numerous other secondary copper minerals.