Quantcast
  We apologize for any slow response. This will be fixed before October 31st Portal logo
Login/Register
Bactrian Gold Treasure from Afghanistan, coming soon....
/gemstones/king-natural-history/page_148 - 2
 

Callais, Turquois

Callais, Turquois Page of 453 Callais, Turquois Text size:minus plus Restore normal size   Mail page  Print this page
CALLAIS AND CALLAINA.
139
for green, being applied to a stone now only valuable when of a pure blue. Even in the last century, according to Dutens, many preferred the Turquois of the former tint when pure and un­clouded.5 The very rare antique works in relief remaining to us in Turquois are in this green kind; the principal being the head of Tiberius at Florence, in a stone as large as a walnut, and in full relief; and the busts of Livia and the same emperor when a boy, in half-relief, on a much larger Turquois in the Marlborough Gems,—a work of extraordinary excellence. The same col­lection contains a still greater rarity—a small cameo portrait of a Greek prince in a Turquois beautifully azure, and " de la vieille roche." Antique iutagli upon this stone, owing probably to its want of hardness, do not exist. It was much employed by the Renaissance artists for small heads and for camei; such being the actual origin of almost all these small works, though usually regarded as antique.
The stone has pretty much the same chemical constituents as the Lapis-lazuli, but seems rather softer, and for the most part becomes decomposed and chalky by long lying in the earth, as is often to be seen in those set in the jewels only a few centuries old.
Mohammed Ben Mansur says the best Turquois come from Nishapur, others from Ghasna, Irak, and Kerman. Of the first he makes seven varieties, according to their degrees of hardness and their tints : that named after Abu-lshak being the best, and the Andelibi (of a milky hue) the weakest. His fourth, Sermuni, with gold spots, is rather a kind of Lapis-lazuli. As to its pro­perties, it grows clear or dull according to the weather, and on rainy days has a greater circumference than on fine. One sort gains a better colour if steeped in oil, but loses it again. Ac­cording to the time since it has been dug, the Turquois is divided into that " of the Old," and that " of the New Mine :" the latter does not keep its colour.
Few gems were invested with more wonderful properties than the Turquois by the credulity of mediaeval naturalists, a long-list of which are given by De Boot, who vouches for some of the
Callais, Turquois Page of 453 Callais, Turquois
Suggested Illustrations
Other Chapters you may find useful
Other Books on this topic
bullet Tag
This Page