The cracks in garnet are called ice cracks by people in the industry. Ice cracks are common in rock crystal, such as amethyst, tourmaline and ordinary beads.
Cracks: The less, the better. There will be natural ice cracks in natural spar, which is normal for garnet, and it is even more difficult to find none. If there is nothing, it must be the top grade, which is the existence of high price in garnet.
Extended data:
Identification and evaluation:
Visual identification of garnet;
There are many varieties of garnet, among which emerald green and transparent varieties are rare. The price of garnet produced in Mozambique is also very high, and the domestic garnet is mostly black and the price is low. To evaluate the most important color of garnet, the color should be bright and pure, followed by high transparency, so that the processed gem can be bright and "fire"; Thirdly, there should be fewer flaws and beautiful style;
Size factors have little effect on the value of general varieties. It should be noted that there are starlight and cat's eye gems in garnet. If the color is positive and the star line or eyeliner is good, it is a high-value variety.
Although different kinds of garnets have different colors, slightly different refractive index, specific gravity and hardness, all garnets are isomorphic and single-refracting gems without dichroism and polarization. Common gem garnet and its characteristic colors: almandine, maroon; Magnesium aluminum garnet, red; Manganese aluminum garnet, orange yellow; Eclogite, yellow-green; Andradite, green;
Magnesium iron garnet, rose red and calcium chromium garnet, emerald green. As a general connoisseur or customer, you don't need to determine the specific variety of garnet, just know that it is garnet. There are not many gems similar to garnet in the market, mainly ruby, zircon, spinel, synthetic yttrium aluminum garnet, gadolinium gallium garnet and glass imitation.
1, Identification of Garnet from Other Jade:
Rhododendron and red zircon have dichroism, and red zircon also has a strong ghost, while garnet has no dichroism and is easily distinguished from garnet. Spinel is generally light in color and needs detailed identification by instruments. Natural garnets of various colors have some defects or crystal inclusions (such as acicular stone and some gas-liquid two-phase inclusions). ).
Garnet and glass, on the other hand, are usually very clean, or have spherical clastic bubbles, which are strongly red under Chelsea. In fact, for some specific garnet, it can also have its own unique characteristics. For example, garnet (a green andradite) usually has "ponytail" fiber inclusions.
In addition, the so-called "green pomegranate" in the market has nothing to do with garnet, but is actually prehnite. Prehnite is not a green garnet. These two are completely different concepts. In the market, prehnite and green garnet are tied together for money. Garnet is very expensive, in contrast, diamonds are extremely rare in the market.
2. Identification of garnet and its imitations;
There are few imitations of garnet. It's easy to tell. Distinguishing garnet mainly starts from the following four points:
(1) If the color of garnet is super bright and super transparent, if the price is attractive, go easy, there is a problem.
(2) Look at the impurities in cotton wool. Garnet is prone to black spots and ice cracks.
(3) Garnet is heavier than ordinary crystal. Take it in your hand and weigh it. If it is lighter than powder crystal, you should be on your guard.
(4) Garnet is delicate, the surface feels smooth, it feels comfortable and oily ~ and it has a cold feeling in your hand, which is very refreshing, not the "glass" feeling of powder crystal.
Garnet instrument identification:
Garnet-like gems include ruby and red spinel. Ruby is anisotropic, with dichroism, characteristic chromium absorption spectrum, obvious fluorescence reaction, flat strip shape, and can form an angle of120 with needle-like inclusions; Spinel has low refractive index, fluorescence reaction and octahedral inclusion.
Garnet is isotropic, has no dichroism and has no reaction under Charles microscope. Garnet may have ponytail inclusions. High-quality hydrogrossular is bright green, very similar to jade. There are often black spots in hydrogrossular, and the refractive index is 1.73, and the red area has no characteristic absorption.
Garnet evaluation criteria:
(1) color:
The lighter the better, garnet is naturally heavier than other crystals, so light color is hard to come by! The one that looks like black at first glance is the worst. In addition to special garnet, red garnet is also common, but the price of red will vary according to the depth of color.
The highest price is purple garnet, followed by rose and wine red. On the basis of these colors, the lighter the garnet, the higher the price, and at first glance, the garnet that is so black is the inferior garnet.
(2) Inclusion: The less, the better.
(3) Cracks:
The less the better, the natural spar will have natural ice cracks, which is a normal performance for garnet. Without it, it is more difficult to find anything! If there is nothing, it is absolutely top grade. It must be the existence of high price in garnet.
It is normal for garnet to have ice cracks, but the less ice cracks, the better. In fact, all crystals are like this. There is no absolute, only relative.
(4) Crystal permeability:
The more transparent the crystal, the higher the price. A good garnet bracelet will shine through the whole crystal under the irradiation of a single light source, just like a full pomegranate seed, which is extremely attractive. And almost no garnet or artificial garnet will have such a good effect.
(5) overall texture:
The top garnet has bright surface and strong luster. The price of garnet with good texture is much higher than that of similar garnet with low texture.
References:
Baidu encyclopedia-garnet