Calcite is just a kind of calcium carbonate mineral, which is called calcite in English. It is the most common natural calcium carbonate. Therefore, calcite is a widely distributed mineral. Calcite has a variety of crystal shapes, and their aggregates can be clusters of crystals, granules, blocks, fibers, stalactites, soils and so on.
Identification method of natural topaz
1, touch mode
Crystals are all crystals with fast heat transfer, while glass is amorphous with slow heat transfer. Therefore, holding the crystal will make you feel cold, and after wearing it for a short time, it will synchronize with your body temperature; And glass has a sense of temperature.
2. Observation of inclusions
When observed with a jewelry magnifying glass of 20 times, defects such as gas-liquid inclusions, flocs, raw minerals, ice cracks, peeling and so on often appear. And most flawless crystals have problems. Swirl-like thin lines often appear on the surface and inside of glass.
3. Fracture identification
Everyone is familiar with the broken pattern of glass, which is smooth and curved like a dent in a shell; Crystal is an ore, the texture of the stone can be seen at the fracture, and the crystal is a crystal, and there will be no traces like glass on the cross section.
4. Technology
The more precious a gem is, the finer it is polished. For example, the cutting of diamonds has become an art. The fake glass gemstones are cheap, so the polishing is rough, the surface is uneven, the intersecting edges between facets are not straight, and the small holes are not delicate-especially this small hole is brittle and easy to break at the small hole, which is just for fracture observation.
5. Optical identification
Glass is an amorphous isotropic body and crystal is a crystalline anisotropic body. The rock crystal that turns 360 degrees under the polarizer looks bright and dark, but it is actually a fake crystal that has not changed. In addition, some rock crystals, such as amethyst, have dichroism, while pseudocrystals do not.
6, hardness distinction
The hardness of crystal is 7, and that of glass is about 5.5, so when crystal cuts glass, there is no trace of crystal, but there is trace of glass. If you like, you can try it on the glass in the part where the jewelry is not obvious. ) Love tip: Hardness test is only for crystal gemstones. Don't use this method to identify non-crystal treasures, such as organic gems such as beeswax, coral, pearls, or jade. In addition, from the gemological point of view, hardness and brittleness are two concepts, that is to say, hardness does not mean that it is not bad to fall, so we must first understand the specific physical properties of the baby before doing it, and don't be too barbaric when wearing it.