Gem Testing

2007: Farn's views on how to run a gem testing lab as a business + working with endlessly complicated clients should provide insights for today's lab gemologists.

(via The Journal of Gemmology, Vol.10, No.1, January 1966) A E Farn writes:

Gem testing could well be the title of a book, a lecture, or merely the sum of all that gemological students imagine is the itinerary of a laboratory gemologist’s day.

Gem testing, generally speaking, is a mixture of items in infinite variety; and if variety is the spice of life—ours is spicy. We are fortunate in having no strictly routine work (in an orderly sense), but because of gemological classes, trade associations and earlier retail experience, we are fortunate in having contact with many aspects of the trade.

Gem testing to the student is usually visualized by stones being tested on the refractometer, or careful wavelength measurement by a spectroscope, crossed-filter work, immersion inspection by microscope, suspension in jars of clerici solution or density work by balance—plus, of course, the mysteries of the endoscope, that unique instrument understood only by a few and capable of use only by the very dextrous, X-rays, fluorescence, phosphorescence, short wave lamps and electro-conductivity tests on rare and pale shades of diamonds. These together with immersion contact photography, Lauegrams and direct radiographs, all join to add to the importance and interest of gem testing.

Strangely enough, a good sense of color, cut and make of stones together with a 10x lens still remain the most useful versatile and flexible adjuncts to the trained gemologists. Gemology, and by that I mean ‘jewelry’ testing, is basically a bread-and-butter science revolving chiefly round the stones which matter: stones such as diamond, emerald, sapphire, ruby, chrysoberyl, peridot, tourmaline, topaz, zircon, quartz, spinel and beryls. These together with opal, pearl, and turquoise, constitute the major importance in the world of gems.

Practically all the money in the gem trade is made by use of these stones in settings of precious metals. The occasional advent of a rare stone in jewelry is interesting to the collectors and non-trade gemologists. Here lies their skill and expertise. Many non-productive hours may be spent in the pursuit of interference figures, refractive indices, indications of positive or negative signs in uniaxial or biaxial stones. Enjoyable as these results may be, they net no cash and cash spells quite a lot of useful things even to gemologists non-trade.
However, fortunately for us, there are still a lot of people who want to know what the center blue stone in a cluster is, or whether the emerald in their Aunt Jane’s pendant is real or not. Probate valuation of deceased person’s jewelry, where the beneficiaries cannot agree as to who have Aunt Maria’s pearls, can be a very useful source of gem testing, for here even the smallest items must be detailed, if only to please the Inland Revenue.

All in all, gem testing, whilst varied, is mundane and concise—very ordinary jewelry set with usually quite small gemstones or pearls of the well-known varieties and, like many other trades or professions, it always seems more interesting to the non-participants. Like watching a plumber wiping a joint—someone else’s job always makes my fingers itch, which brings me to a case in point.

A very good friend of mine, watching with keen interest a test being carried out on a customer’s ring said, ‘You know, you go the wrong way round in your testing. You fly to the most spectacular instead of the more fundamental test in routine matters.’

Here was a challenge flung down on our own doorstep. However good an amateur may be (and he may well be ten times enthusiastic as the professional)—he does testing for love whereas the professional does it for money.

To a professional gemologist, even though he may be a little jaded, the challenge remains constant. He might be right, backed by incontestable facts. To say his facts must be crystal clear (as the gemologists punned it) are the remarks of a gemological pundit.

Gem Testing: ( continued)