The spinel and ruby occur together in nature, stones from Burma being as often spinel as true Oriental ruby.
The hardness of spinel is 8, or about that of topaz, and the specific gravity 3.6.
The natives of India call the spinel the pomegranate ruby and believe to this day that it possesses valuable medicinal properties.
spinel is thus known among gems chiefly as a relative of the ruby, and this sort of spinel will first be considered.
The true topaz is a bit softer than spinel, and the rough crystals show a very perfect basal cleavage.
The spinel rubies differ from the true or corundum rubies in hardness, specific gravity and system of crystallization.
Mrs. Todd's brother got kicked in the spinel string (cord) with a mewel an' he died the same nite.
spinel is singly refracting in polarized light and corundum doubly refracting.
Mention has been made above of a stone frequently substituted for the true ruby, called the “spinel” or “balas” ruby.
The spinel ruby of the French crown jewels, weighing 56 carats, was in 1791 valued at ten thousand dollars.
|spinel also spinelle |