Jewelry Lovers

The blue-tinged turquoise can look back upon the same rich and honorable tradition as lapis. While other stones have risen on the horizon of fashion and faded away again, turquoise has retained its favor unharmed over thousands of years. Egypt’s Pharaohs already venerated the captivating beauty of its lustrous blue to greenish-blue color four thousand years before the Christian era, when they mined the unattractive raw material in the Sinai peninsula for their lavish jewelry. From this epoch date the bracelets ornamented with little gold plates and engraved turquoises as well as the most diverse figure carvings, which were found in the tomb of Queen Zur, consort of the Pharaoh Athotis.

Like malachite, turquoise is a secondary mineral; it developed near the surface from the effect of solvent and percolating meteoric waters, primarily in magmatic rocks in which the ascending underground and the descending rain waters displaced feldspar minerals by their hydrothermal solvent power and dissolved important components from the country rocks; these formed new deposits of turquoise by precipitation from the circulating waters. Chemically speaking, the mineral is a complex hydrous copper-bearing aluminum phosphate. The strong sky blue can be ascribed to a constituent copper content of less than i o percent; thus turquoise is ranged within the group of idiochromatic ornamental stones. If traces of iron take the place of copper, the coloring takes on a less admirable greenish tinge. Until recently, when for the first time turquoise became known in obviously triclinic crystal form in the U.S., it was regarded, like opal, as an amorphous stone. After the age-old Sinai mines became largely worked out by the Egyptian slaves, Persia came indisputably into the first rank before the fairly important turquoise-bearing beds of Nevada and Afghanistan.

The loveliest light to forget-me-not blue specimens with a fine waxy luster are produced from the famous deposits in the Kuh-i-Binalud mountains, northwest of Nishapur. The older sedimentary rock is here intruded, and in parts even metamorphosed, by younger volcanic rocks consisting of porphyritic trachytes and felsite porphyries, so that turquoise occurs filling cracks and cavities in the brecciated trachyte, and spreading as a closely branching network of narrow veins from 2 to z o millimeters thick. It was at the same time completely or partly enveloped by the older mineral limonite and intergrown with reticulate patterns, thus producing the turquoise matrix so much prized in the West. The material is not only wrung laboriously from its primary source, but often from weathered masses, talus debris, and water-laid sediments too. New turquoise occurrences have recently been traced in northeast Tanzania in the Gilewi Hills.

Pliny’s observation that kallait or kallalite—derived from the ancient Greek name kalos lithos = “beautiful stone”—could be affected by oils, unguents, and wine is still valid. Turquoise received its present name later, when it entered the European trade via Turkey and the French therefore designated it the pierre turquoise, which subsequently became shortened to turquoise. The December stone, turquoise, was eulogized by the oriental poets as talisman of riders and as protector of innocence and good fortune; probably its age-old link with the destinies of mankind may therefore well account for its being veiled in powerful magic. Few gemstones have served to build so harmonious a bridge between the ancients’ concept of ornament and the present-day feeling for fashion as turquoise.

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