How to identify gems

Title

Creator

Untermeyer, W.

Language

English

Year

1965

Rights

In Copyright - Educational Use Permitted

Fulltext

HOW TO IDENTIFY GEMS The Gemological Institute of America, owes its origin to the curiosity of its founder, Robert Shipley. In the early 20s Shipley became the pro prietor of a retail jewelry store in Wichita, Kansas, by the simple expedient of mar rying the boss’ daughter. A conscientious individual by nature, Shipley felt keenly his lack of knowledge of the jewelry business. The main source of information was the often inaccurate word of the traveling salesmen. The only textbooks dealt with gems from minerological con siderations. When circums tances compelled him to close his store, Shipley went to England where he could receive a formalized training in gemology. Late in 1929 Shipley re turned to this country to ap ply his newly acquired know ledge to the operation of a jewelry store in Los Angeles, but America was in the midst of panic. He decided to es tablish himself as a consul tant in anticipation of more propitious times. A group of jewelers prevailed upon him to give a series of lec tures at the University of Southern California. Over eighty jewelers registered, some coming from a distance of over 200 miles. Soon Shipley was mailing his lectures throughout the country and, in 1931, the Gemological Institute of America had its official beginning. Many old timers still pride themselves on their ability at sight identification. A customer returned a ring with a large purplish stone to the jewelry store where it was purchased. The ring had been dropped on the bathroom floor, and the stone had shattered. Since the jeweler had bought the stone for amethyst and under the impression that genuine stones are durable, he return 48 Panorama ed the ring to the manufac turer with an outraged let ter demanding immediate re placement. The manufac turer agreed that a stone which had so fractured could only be an imitation and as such, not the stone he had sold. The argument was re ferred to the Gemological Institute of America who confirmed that the stone was indeed amethyst which, while less fragile than glass, is highly breakable when subjected to a blow of suf ficient severity. Transparent or translucent stones may be separated into species with the use of a re fractometer, an instrument which measures the degree of bending of a light ray pass ing through a stone, in con junction , with a polariscope, an instrument for determin ing the crystal structure. Imi tations are easily detected, but synthetic stones similar to the genuine in every che mical, physical and optical property are occasionally very deceptive, particularly in the small sizes running any where from ten to fifty to the carat. Tiny gas bubbles and curved striae detectable under high magnification by a skilled technician provide the clues. Dealers who em ploy the institute consultants are sometimes rewarded for their precaution. The most common failing of the layman in recognizing stones is the attempt to clas sify by color. Thus a ruby is red and a sapphire is blue, and conversely any red gem stone is thought to be a ru by and any blue to be a sap phire. The fabulous ruby which for five hundred years graced the imperial crown worn by the rulers of Eng land and described by Rus kin as “the loveliest precious stone of which I have any knowledge” has been proven under modern instrumenta tion to be a red spinel, a ma terial ordinarily less valuable than ruby, but nevertheless of great rarity since spinels so large in size are almost unknown. Since coloring is caused in most gems by foreign material and is not a part of their che mical component, stones can occur in a variety of shades. Sapphire, tourmaline and quartz have been found in every color of the spectrum. October 1965 49 Ruby and sapphire are ac tually the same material. Ruby is merely the name given to the red variety. Amethyst is a purple quartz. Emerald and aquamarine are the identical material. Eme rald is infinitely more valu able because of the dearth of fine green beryl in large crystals. Even the fabulous diamond has been found in all colors except purple, and that is not to say that the diamond does not occur in purple but merely that no natural specimen has been discovered as yet. The fa mous Hope diamond is a wonderful rich blue more re miniscent of fine Ceylon sap phire. Precious topaz, popu larly known as a brown stone, has been found in all colors with blues and pinks as the loveliest varieties. With some gem materials color changes can be induced by baking the stones in a fur nace at temperatures which duplicate the heating process in nature. In a few species such as topaz this entails a risk of cracking the stone. — W. Untermeyer, Jr. from the American Mercury. ACHIEVEMENT BY COLLABORATION It is because the earth is round that we have become human: you see, we could not get away, we Could not help but rub against each other; and this rubbing polished our minds, sent the mental temperature up; in such heat minds became flexi ble, moved with speed; became involved and con voluted and related in ten billion ways. Now, sud denly today, we are only a few hours from every man on earth, and our minds are showing a start ling leap forward toward complexity: men in small groups, collaborating, can solve problems in a few weeks or months or even days that one man, work ing alone and in isolation, could never have solved had he lived a thousand years. — Teilhard de Chardin. 50 Panorama

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