Calamine is the common name of two zinc ores - one being a hydrous silicate also known as smithsonite, hemimorphite, or electric calamine; the other being the carbonate. Both occur frequently in veins which carry zincblende, the commonest of the zinc ores. They are pale yellow, pink, brown, blue, green or colourless and are often mixed in a fine powder known to miners as ' dry bone'. Calamine is used in medicine as a skin soother to relieve rashes and other skin irritations. Research Calamine
Hemimorphite has the formulae Zn4Si2O7(OH)2ùH2O. It has a relative hardness of 5. It is an ore of zinc. Found in the oxidized regions of zinc deposits. Research Hemimorphite
Prehnite is a mineral named after Colonel Hendrick Von Prehn who first discovered it at the Cape of Good Hope in South Africa. It was confirmed as a distinct species of mineral in 1788. Prehnite is a hydrous silicate of calcium and aluminium with the formulae Ca2Al2Si3O10(OH)2 and a relative hardness of 6 to 7. Prehnite occurs as a crusty lining in cavities in basalt and related rocks and is associated with zeolites, datolite, pectolite, and calcite. Prehnite has a characteristic green colour. Resembles hemimorphite but is of a lower specific gravity and fuses easily. Research Prehnite
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Matt and Leela Probert
Abbreviations
Research Calamine
