Sec. II, Ch. 12: The Carbonado Diamond

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	CHAPTER XII.

	CARBONADO.

	HIS substance, also known as "Carbonate" or " Carbon" was discovered in Brazil in 1845, and occurs in small irregular masses of a dark grey, or even black colour. Both the names, Carbonado and Carbonate, are clearly misnomers, as chemically, the body referred to is, like Diamond, Graphite, and Charcoal, a form of the element Carbon. It appears to consist of an irregular aggregate of small crystals, and presents on fracture a granular or crypto-crystalline structure. It is found in Brazil, mostly at Chapada, in the province of Bahia ; and in the island of Borneo ; but has not been found either in India or at the Cape. Carbonado though of slightly less density than the ordinary Diamond, is immensely superior to it in hardness. It is, in truth, the hardest known substance in nature, surpassing even Bort, which, in its best varieties, is a trifle harder than the Diamond. Carbonado was at first introduced for the purpose of cutting Diamonds, after the same fashion as Bort. During the last 25 years, however, a new and most impoitant application of this material has been made. It is now very extensively employed for the purpose of drilling holes in rocks, either to receive explosives for subsequent blasting, or for prospecting, in order to discover their underlying strata. The demand that has thus sprung up for

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