A small quantity of zinc is mined in Dumfriesshire and of barytes at Lochwinnoch in Renfrewshire.
Its common adulterants are iron oxides, powdered barytes and brick dust.
Crystals of barytes are orthorhombic and isomorphous with the strontium and lead sulphates (celestite and anglesite); they are usually very perfectly developed and present great variety of form.
Other minerals, which are not found in commercial quantities, are lead in the form of galena, in Sussex county; graphite, in the crystalline schistose rocks of the Highlands; molybdenum, in the form of a sulphide, in Sussex county; and barytes in Mercer and Sussex counties.
Barium occurs chiefly in the form of barytes or heavy spar, BaS 04, and witherite, BaCO 3, and to a less extent in baryto-calcite, baryto-celestine, and various complex silicates.
There are manufactures of leather gloves and other goods, and in the neighbourhood barytes and coal mines and extensive market gardens.
Barytes is of common occurrence in metalliferous veins, especially those which yield ores of lead and silver; some of the largest and most perfect crystals of colourless barytes were obtained from the lead mines near Dufton in Westmorland.
Considerable quantities of the following minerals have been found: barytes (heavy spar), magnetite (magnetic iron ore), and pyrolusite (manganese dioxide) in Humboldt county; roofing slate in Esmeralda county; cinnabar (ore containing quicksilver) in Washoe county; haematite in Elko and Churchill counties; cerussite and galena (lead ores) in Eureka county; and wolframite (a source of tungsten) at Round Mountain, White Pine county.
Throughout the world, primary deposits of tinstone are in or closely connected with granite or acid eruptive rocks of the same type, its mineral associates being tourmaline, fluorspar, topaz, wolfram and arsenical pyrites, and the invariable gangue being quartz: the only exception to this mode of occurrence is to be found in Bolivia, where the tin ore occurs intimately associated with silver ores, bismuth ores and various sulphides, whilst the gangue includes barytes and certain carbonates.
Crystals of barytes may be transparent and colourless, or white and opaque, or of a yellow, brown, bluish or greenish 'colour.