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Although we place the ruby fourth among the precious stones, so few are the superior rubies in commerce, or that the world sees, that when a perfect ruby of the weight of ten or more carats enters the market, it brings a price three times as great as does a diamond of the same weight.
The natives of India indiscriminately apply the name "ruby" to all coloured precious stones, and it is the habit of American dealers in precious stones to be almost as general in calling various red gems rubies, although they do distinguish by calling the corundum ruby "Oriental ruby." This being a book for every-one, other red stones commonly or even occasionally appearing in the jewelry trade and called by merchants rubies will be comprehended and described in this chapter, leading with the corundum reality, which is beyond compare.
Corundum crystallises in the hexagonal system in six-sided prisms and pyramids, the crystals frequently being rough and rounded; hardness 9; brittle; specific gravity 3.9 and upwards to 4.16; lustre adamantine to vitreous; sometimes the lustre is pearly on the basal plane; and occasionally there is exhibited a bright, opalescent, six-rayed star in the direction of the vertical axis. The colour range is almost unlimited, blue corundum being sapphire. The strongly coloured varieties are pleochroic. Corundum is sometimes phosphorescent, with a rich red colour. The red-coloured corundum or ruby varies from a rose to a deep carmine, the desideratum being a "pigeon's blood" red, and the same crystal will sometimes reveal different colour. Like its brother in the noble corundum family, the ruby is a peer of the realm of precious stones, and second only to the throne of the sovereign diamond. |
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Precious Stones Guide Vol 4
>> About the Properties of Rubies and Their Value in the Twentieth Century
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