Antimony
This is a brilliant white metal of a crystalline texture and bluish white color, and so brittle that it cannot be rolled into sheets nor drawn into wire. Its specific gravity is 6.71; melts at 810 deg., crystallizes in pyramids, and volatilizes at an intense heat. There are several varieties of the ore, but the sulphuric, or gray antimony, is the most abundant, and yields the metal of commerce. To reduce the ore it is first made into a powder, after which it is heated in a reverberatory furnace; the melted sulphuret then flows from the infusible earthy matter, and is subsequently smelted and purified. Exposed to the air at ordinary temperatures antimony does not rust; this property, combined with its hardening influence on other metals, renders it eminently useful in the composition of many useful alloys to make them harder and whiter.
It is usually found associated with other metals, but always contains more or less iron. The crude metal, or sulphuret, is employed for purifying gold, the sulphur from which being readily absorbed by the inferior metals, while the antimony unites with the gold. Antimony has generally been distinguished as Regulus, or petty king, because of the hardening influence previously mentioned; alloyed with an equal quantity of tin we have a brilliant white and somewhat hard alloy suitable for some descriptions of specula. Sodium and potassium are the metals with which antimony unites the most readily, as, even when the former are alloyed with other metals, the association is found to be of an intimate character. Antimony readily combines with gold, but destroys the ductility of the latter, producing a granular alloy of a golden tint, the depth of which is proportionate to the amount of gold present. Antimony contracts little or none in cooling. For this reason it is doubly valuable in the production of types, music and other plates, etc., as, besides giving the requisite degree of hardness to such alloys, it enables the founder to obtain a true copy of the matrix--something almost impossible in most of the other metals employed for this purpose, owing to their high shrinking qualities.
For a large variety of alloys in which antimony enters as an ingredient, see WHITE ALLOYS; TYPE-METAL; ANTIFRICTION ALLOYS; PEWTER; BRITANNIA METAL; QUEEN'S METAL; MUSIC METAL; SPECULUM METAL; SOLDERS.