BARYTE, CERUSSITE and GALENA (miniature)

Baryte, also known as barite or barytes, is a mineral composed of barium sulfate (BaSO4). Typically appearing white or colorless, barite serves as the primary source of barium. The baryte group includes barite, celestine (strontium sulfate), anglesite (lead sulfate), and anhydrite (calcium sulfate), with barite and celestine forming a solid solution represented as (Ba,Sr)SO4.

Cerussite, also referred to as lead carbonate or white lead ore, is a significant mineral composed of lead carbonate with the chemical formula PbCO3. Its name derives from the Latin term "cerussa," meaning white lead. The mineral was first noted by Conrad Gessner in 1565, and in 1832, F. S. Beudant introduced the name céruse, while the current designation, cerussite, was established by W. Haidinger in 1845. Historically, miners referred to it as lead-spar or white-lead-ore. Cerussite crystallizes in the orthorhombic system and shares isomorphism with aragonite, often exhibiting twinning that results in pseudo-hexagonal forms. Typically, three crystals are twinned on two prism faces, creating six-rayed stellate groups that intersect at nearly 60-degree angles. The crystals are commonly bright and smooth, but the mineral can also appear in compact granular or fibrous forms, usually colorless or white, with occasional grey or greenish hues. It ranges from transparent to translucent and possesses an adamantine luster, with a Mohs hardness of 3 to 3.75 and a specific gravity of 6.5. A variant known as iglesiasite, which contains 7% zinc carbonate replacing lead carbonate, is found in Sardinia. Cerussite is easily identifiable by its distinctive twinning, adamantine luster, and high specific gravity, and it effervesces when dissolved in dilute nitric acid. A blowpipe test reveals its readiness to fuse, indicating the presence of lead.