The Encyclopedia of Founding

Twelve hundred entries from the golden age of cast metal — how bells are founded, why brass is not bronze, what a cupola melts and a core withstands — by Simpson Bolland, the trade's great teacher.

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Diamond

The purest form of carbon known. It is a crystal of the greatest purity and hardness known. Several localities in India, the island of Borneo, and Brazil furnish this beautiful substance. Diamonds possess a very high refractive and dispersive power, by which they flash the most varied and vivid colors of light. The diamond is a non-conductor of electricity, and resists the action of all known chemical substances. It is infusible and unalterable even by a very intense heat if air be excluded; but when burned in oxygen gas, the combination forms carbonic acid gas, hence its composition is pure carbon. Heated to whiteness in a vessel of oxygen it readily burns, yielding carbonic-acid gas; hence its composition is pure carbon (specific gravity, 3.5). A diamond is of the first water when perfectly colorless. Artificial diamonds are made from a paste composed of pure silica 100, red oxide of lead 150, calcined potash 29, calcined borax 11, arsenious acid 1. This composition fuses at a moderate heat, and if the alkali is expelled by the continued fusion it acquires great brilliancy. See PRECIOUS STONES; CARBON.

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