How to distinguish a genuine gem from a fake

By Roland M. Sutrisno

JAKARTA (JP): People often say that two grams of a precious stone can be exchanged with two truck-loads of gravel or river pebbles. Precious stones or gemstones are so valuable that they easily command high prices.

We therefore need to pay special attention to the gemstones we usually wear. A gemstone may be a heirloom, a gift from a friend, an intimate friend, a find from a river or a railroad track; it may come from a sidewalk booth, a plaza or a mall. It is important that we know the difference between a natural gemstone and a synthetic one. The majority of precious stones now in circulation (nearly 60 percent) are imitation or synthetic ones, says gemstone expert Sam Han Kay.

Indeed, synthetic stones are beautiful to the eye. They are usually made from natural stones through a chemical process which involves a temperature of several thousand degrees, an application of striking colors, and polishing here and there. The result is gemstones carrying a luster of beauty and distinction. Synthetic stones are manufactured by a processing machine aided by laser rays to yield the colors desired by a purchaser. The resulting colors are perfect.

Imitation stones have an even wider circle of users due to their attractive lower prices. These stones are indeed made of varied colors of glass or perfume bottles which have been liquefied, and are molded in such a way as to take a form that is "genuine".

Now, having read this article you must be prepared for a heart attack. In other words, do not be startled if a so-called genuine gemstone you are wearing is a fake and is just plain glass. How to distinguish the genuine gem from the fake one?

It is certainly not difficult to recognize a genuine precious stone if you are used to looking at it. For a layman, however, it is indeed very hard to tell the difference between a genuine and an imitation stone. It may happen that the stone is natural but its colors have been processed, creating brilliant colors, even a "star".

Characteristics

The following are the characteristics of a genuine stone:

1. Natural veins: Existing lines in a transparent stone. The natural lines look to us exactly like veins, only they appear as fine as hair. To have a better look you can use a 10- or 20-fold magnifying glass. You may also resort to a microscope.

2. Form: From its form we can see if the underpart is rough or as smooth as molded work. If it is smooth, it is nearly certain that the stone is an imitation or glass, because a fake stone has a perfectly neat basis that a genuine stone does not possess. Moreover, the underpart of an imitation stone is somewhat concave. A genuine stone has a rather rough undulated underpart. The smoothness of a stone is certainly the result of scouring, either by machine or abrasive paper.

What about stones cut into the form of diamonds, while the upper part is round or flat? This form is rather difficult to distinguish. We can give proof by another method.

3. Bubbles in stones: We can find the characteristics of genuine stones by the bubbles inside the stones. They are visible under the naked eye or with a 10- or 20-fold magnifying glass.

Another aspect requiring our attention is that the edges of the bubbles in the stones are dented and not even. This is clearly visible when we compare genuine stones with imitation ones.

A word of caution, though, to those wanting to use a magnifying glass in front of a jeweler. He may be angered at someone inspecting his merchandise with a magnifying glass. He could be offended if the genuineness of his stone is doubted.

If the stone is an imitation, smooth bubbles with even edges will almost certainly be seen. If it is still difficult to see the difference, compare the imitation stone with some clear glass at home. There are stones showing no bubbles at all, even when viewed with a 20-fold magnifying glass. In that case we have to use another method.

4. Colors: If a magnifying glass does not show any bubbles in a stone, we look for the most dominant color. If the color is brilliantly and radiantly clear, and attractive, we can guess that the stone is genuine, although it is only lit by natural lighting and not by a focused light or a flashlight. What about the cut underpart of the stone like a diamond? It can be differentiated if the stone emits rays and the colors in it are uneven. The color appears like a gradation. A magnifying glass clearly shows it. It is sufficient to use a 10-fold magnifying glass.

What about non-transparent stones? We can tell the difference from the colors. The important thing is that the stone reflects light even when only given a cursory rub. If you are used to seeing gemstones or jewels you will see the difference.

In case of an imitation stone, its colors will look like added colors to jelly or candy. However, it will be very hard to rely on the criteria of color, because some kinds of stones look exactly like candy. Topaz is yellow or white, emeralds are green, rubies look like FOX candy. So, the criteria for colors to inspect the genuineness of stones are nearly impracticable as the best guide.

5. Veined: A genuine stone will appear veined if we hold it in sunlight or if we put a light underneath it. An imitation will certainly not show veins. The veins appear naturally over a period of millions of years and are the result of the stones being deep in the earth.

6. Misty: A genuine stone will clearly show some mist like a cirrus or cumulus clouds with graded colors. If a stone shows a lot of mist or cloud it is fairly certain that it is genuine. An example is a stone with much mist such as the amethyst which is violet.

7. Chicken feathers or insect wings: A genuine stone looks like it has a chicken feather or an insect wing floating in the stone. This can be seen in the blue sapphire or the clear and transparent ruby.

8. Refraction of a stone: The refraction of a genuine stone can be tested with a refractometer which tests the light reflected by natural stones.

9. Diamond Tester: It is different with diamonds. An instrument to test whether a diamond is genuine or not is the Diamond Tester which, upon contact with a diamond, will give a sound even with the ugliest and cheapest diamond. This instrument tests diamonds only and not other gemstones.

10. Emerald Telescope: The telescope to test emeralds is especially designed to test emeralds and is equipped with a special filter. It readily shows whether the emerald is genuine or fake. A genuine green emerald will look red with the telescope. A fake emerald will remain green.

11. Feeling: The most important factor and one that is a human aspect is feeling. If we are used to looking at stones, every day, every hour, every minute, we can certainly tell the difference immediately. A stone will "speak" to us, whether it is genuine or fake. This factor is very hard to describe in detail and extensively. If we know genuine stones closely by continuous investigation, a feeling will gradually grow to discern the genuine from the fake.

Let us not lose courage if the stones we wear are imitations. Perhaps the element of subjectivity makes us happy. If we are happy with the stones we wear, especially if they are heirlooms, we need not lose heart.

Once again, spiritual satisfaction is a very important factor. Whether you use genuine or imitation stones, it is up to you or to your pocket.

-- Roland M. Sutrisno is collector of precious stones