You will need
- - strong magnifier;
- - Refractometer;
- - color filter.
Put the stone on a white sheet of paper and evaluate its color. All the emeralds are colored in different shades of green. If the colouring are yellowish tone, most likely in front of you green garnet or peridot. Green emeralds have a bluish hue.
Under the bright light, turn the stone. Pay attention to variance. Gemologists call this word flashes or sparks of light generated due to the different inclusions. At emeralds the dispersion level is low, so the natural stones give a little "fire". If the gem sparkles and shimmers, most likely, before you cubic Zirconia.
Check the stone on the Refractometer. The refractive index of the emeralds is approximately 1,58.
Green, which is so sought after emeralds, occurs due to the large presence in the composition of the mineral chromium. So the emeralds under the color filter looks brown or red. But the filter does not allow to distinguish natural emerald from synthetic.
Exactly the same shade underneath the filter has a green fluorite, but it is much softer than emerald and is easily scratched even glass. Fluorite under ultraviolet light fluoresces a violet light. At emeralds and luminescence, and fluorescence are rare and usually have red or green.
Carefully inspect the faces of the stone. Very common imitation of emeralds, called "doublet" or "triplet" Is like a sandwich of glass, green epoxy and thin slice of low-quality emerald. When viewed from the side forgery can be clearly seen.
Note the "worn" edges. The Mohs ' hardness of emeralds is quite high, so they remain faceted. Glass imitations quickly wear out. Under a strong magnifying glass is clearly visible.
Natural emeraldx is always present and foreign inclusions. They are clearly visible under a magnifying glass or a microscope. Therefore, the emeralds seem a bit muddy. All these cracks, bubbles and feathers do not damage the minerals. Jewelers call this effect the term "Jardin" (from FR. "the garden"). In-grown stones such defects almost never occur.
Interestingly, some gems-imitation, for example, transparent jade or green garnet-demantoid high quality may have a higher price than a natural emerald of medium quality.
Specify the origin of the stone. The color of Colombian emeralds is due to vanadium, not chromium, so under the color filter, they remain green.
Advice 2: How to determine the authenticity of the stones
When buying jewelry for the authenticity of the stones quite often raises some doubts. An experienced gemologist or jeweler can easily determine the authenticity of any stone. But not always, the buyer has the opportunity to seek the advice of a specialist. Accordingly, the question arises on how to determine the authenticity of the precious stones themselves.
To determine the authenticity of precious and semi-precious stones at home, you must know some of their features. Buying emerald, carefully examine the surface of the stone. In its structure should be visible distinctive pattern. Do not buy a stone that has in its drawing a spiral or tubular patterns, most likely it is a synthetic fake. Buying emerald, take him in hand – to touch, he, like many natural gemstones, should be quite cool.
Choosing ruby, don't be tempted by the stone bright color of blood for a small price. Rubies of large size with bright saturated color are very rare and the cost can get close to the diamonds.
Topaz the feel is smooth and slippery, but despite the fact that its surface can be easily polished look on the stone's natural imperfections. If the seller offers you absolutely pure Topaz, before you synthetic fake.
Sapphire is the stone that is fake much more often than other precious stones. When buying you must be very careful. To touch the sapphire should be cold, like emerald. Synthetic fake, you will notice gas bubbles.
To determine the authenticity of amber can help you get a piece of woolen cloth. RUB it stone – natural will beat the current, attracting the dust, thread and so on.
Fake pearls are way too available price, real pearls for cheap not buy. If you have the opportunity, try pearls on a tooth, the real stone will creak.
Choosing the amethyst, it is necessary to carefully study the structure of the stone, which must have natural defects and blotches.
If you go to the jewelry store to buy jewelry from precious stones, to begin with please be a tenfold magnifying glass. With its help, you better consider natural defects and blotches, which have a natural gemstone.