This section is from the book "Materia Medica And Therapeutics Inorganic Substances", by Charles D. F. Phillips. Also available from Amazon: Materia medica and therapeutics.
This substance, which is now classed among metalloids, occurs native, but in small quantities. It is usually found in alloy with various metals, chiefly iron, lead, and arsenic, and from these its purest commercial samples are seldom quite free. Traces of it occur also in some chalybeate waters, and its oxide constitutes the "white antimony ore" (valentinite): its most common ore is the sulphide, from which crude antimony is obtained by fusion with iron, or by roasting and reduction with charcoal.
When pure, it is silvery white in color with a tinge of blue, laminated in structure, brittle, and crystalline; it is heavy (sp. gr. 6.7) and permanent in the air at ordinary temperature. In its chemical relations it is allied to nitrogen and phosphorus, and still more closely to arsenic.