Quantcast
  Due to a new server, slow response may occur for which we apologize Portal logo
Login/Register
Bactrian Gold Treasure from Afghanistan, coming soon....
/gemstones/king-gems-decorative-stones/page_073 - 2
 

Callais, Turquois

Callais, Turquois Page of 384 Callais, Turquois Text size:minus plus Restore normal size   Mail page  Print this page
64
NATURAL HISTORY OF GEMS.
fourth sort, the Sermani, " having spots of gold," can be no other than a shade of the Lapis-lazuli. As to the natural properties of the Turquois, he avers "that it grows clear or dull according to the state of the weather, and on rainy days has a greater circumference than on fine. One species gains a better colour by maceration in oil, but'loses it again after a time. According to the age since it has been dug, the Turquois is divided into that of the Old,* and of the New mine : the latter does not keep its colour." This distinction is still in force ; Turquois " de la vieille roche," however, actually means at present nothing more than one of the best quality, and supposed not to be liable to fade. Nishapur continues to furnish the only Turquois of com­mercial value : they are brought stuck upon rolls of wax by Tartar and Persian merchants to the great fair of Nishni-Novogorod. Lately, some have been brought direct to this country from the foot of Mount Sinai, where they occur in strata of a sandstone rock. This new find is of a remark­ably rich azure, superior when recent to the finest Persian, but (a fatal drawback) liable to change yet more rapidly and capriciously than any of the old. j The above-quoted
* This " Old Mine or Rock," says Chardin, " was in a mountain, Firuz-cos, distant three days' journey from the Caspian. All its pro­duce was reserved exclusively for the Shah; whatever found its way into the market was due to the embezzlement of the miners and their directors ; a source of supply by no means scanty. No wonder, there­fore, that when Chardin was allowed to visit the Treasury at Ispahan he beheld in each chamber the stones in the rough, piled high on the floor like heaps of grain, and the polished filling innumerable leather bags, weighing 45 to 50 lbs. each."
t The unfortunate liability of so costly a stone to lose its colour and therewith its value, exercised the ingenuity of the lapidaries of De Boot's age in devising methods for restoring it. Some, distilled ultramarine in aqua-regia, and polished the spoilt Turquois with the residuum, others, after macerating the gem in aqua-regia, and washing it in vinegar, threw it into ice-cold water. A third and more approved method was to eat away the surface with oil of vitriol ; but of all the recipes (the
Callais, Turquois Page of 384 Callais, Turquois
Suggested Illustrations
Other Chapters you may find useful
Other Books on this topic
bullet Tag
This Page