Antimony occurs in the native state, but is rare; its common ore is antimonite, the sulphide (Sb2S8). Jamesonite and other sulphides of lead and antimony
Bismuth is nearly always found in nature in the metallic state; but occasionally it is met with as sulphide in bismuthine and as carbonate in
Thallium is a rare metal, found in small quantities in some varieties of iron and copper pyrites, and in some lithia micas. It resembles lead
Cadmium occurs in nature as cadmium sulphide in greenockite, CdS, which is very rare. It is widely diffused in calamine, blende, and other zinc ores,
Zinc occurs in nature most commonly as sulphide (blende); it also occurs as carbonate (calamine) and silicate (smithsonite). Each of these is sufficiently abundant to
Occurs less abundantly than nickel. Its chief ores are smaltite and cobaltite, which are arsenides of cobalt, with more or less iron, nickel, and copper.
Titanium only occurs as a mineral in its oxidised state, or as titanic oxide (TiO2). It is a substance which has little commercial value, and
The ammonic carbonate filtrate from the silica is evaporated to dryness, ignited strongly over the blowpipe, and weighed. The residue is tungstic acid, WO3. The
The magnetic properties of certain minerals have long been recognized, and their concentration through magnetism can lay no claim to novelty. A patent was awarded
The gradual depletion of high-grade mineral deposits and the necessity for development of lower-grade deposits, together with the increased demand for nonmetallic minerals, has increased