Baryte is a mineral consisting of barium sulfate (BaSO4). Generally white or colorless, it is the main source of the element barium, an alkaline earth metal. It is found across the world and can be deposited through biogenic and hydrothermal processes or evaporation. Early records of baryte date to the 16th century, when a radiating form gained notoriety among alchemists for specimens found near Bologna, Italy. Carl Wilhelm Scheele determined that baryte contained a new element in 1774, but elemental barium was not isolated until 1808 by Humphry Davy, using electrolysis of molten barium salts. Modern uses of baryte include oil and gas drilling, oxygen and sulfur isotopic analysis, and radiometric dating. These crystals of baryte on a dolomite crystal matrix were found at Cerro Warihuyn in Miraflores District, Peru. This photograph was focus-stacked from 24 separate images.Photograph credit: Ivar Leidus