Diamonds are made of carbon. Diamonds with natural shapes are mostly octahedral, rhombic dodecahedron or nearly spherical (fragments can be other irregular shapes), and their colors are mostly colorless-yellowish. In addition to the very high-grade, flaws (inclusions) can often be seen under a ten-fold magnifying glass, and there are often triangular growth lines on the surface of diamonds.

Diamond is the hardest substance among natural substances, and no other gem can be carved except diamond. On the contrary, diamonds can carve any other gem.

Diamond is a colorless-light yellow high-grade gem with the strongest dispersion and high refractive index (2.42) among natural gems. The processed diamond will appear red, blue, orange and other colors from the table. At the same time, due to the high refractive index of diamond, when light enters the processed diamond, total internal reflection will generally occur, showing a radiant appearance.

Compared with ordinary gemstones, diamonds have the largest thermal conductivity. If the thermal conductivity of spinel is 1, then the relative thermal conductivity of diamond is above 70. According to this characteristic of diamond, thermal conductivity meter is a simple and effective instrument to identify diamond.

Due to the large refractive index of diamond and the standard cutoff ratio, there is generally no light leakage. In other words, looking down from the table of the diamond, you can't see the objects at the bottom of the diamond.

Diamonds are lipophilic, and this property is used for diamond sorting. If you draw a line on the table of a diamond with a pen, it will be an uninterrupted straight line, while other gems are intermittent dotted lines.

Diamond:

Diamonds refer to polished diamonds, which are formed under high pressure and high temperature conditions in the deep part of the earth. (c) Natural white crystals with cubic structure. Diamonds have religious worship and awe, and at the same time they are regarded as symbols of courage, power, status and dignity. Now it has become a popular gem that people can own and wear. Diamond culture has a long history, and some people regard it as a symbol of love and loyalty.

tangible property

Chinese name: diamond, diamond

English name: Diamond

Mohs hardness: 10

Chemical composition: 99.98% carbon.

Physical properties: It has the highest hardness among natural minerals, and its brittleness is also quite high, and it will still break when it hits hard. From the ancient Greek agonist, which means hard and inviolable substance, it is recognized as the king of gems. In other words, diamond is actually a kind of carbon crystal with quite high density.

Common shapes: round, oval, olive pointed, heart-shaped, pear-shaped, square, triangle, emerald-shaped. A round drill is the most common shape.

Refractive index: 2.4 17

Dispersion value: 0.044 (higher)

Total internal reflection: critical angle: 24.5.

Main producing areas: The main producing areas of diamonds are Australia, Botswana, Canada, Zimbabwe, Namibia, South Africa, Brazil and Siberia; At present, the main diamond cutting and grinding centers in the world are Antwerp, Tel Aviv, new york, Mumbai, Thailand and Bangkok. Antwerp has the reputation of "the diamond capital of the world", where about half of the world's diamond transactions are completed. "Antwerp Cutting" is synonymous with perfect cut.

Diamonds are extremely precious, so their weight is expressed in a special unit "carat". 1 carat equals 0.2 grams. At present, the largest diamond in the world is a diamond named Africa Star, which is embedded in the Queen's scepter and weighs 530.2 carats, or 106.04 grams.