Sapphire crystal is an expensive product in the manufacture of which sapphires grown artificially are used. Sapphire is a transparent mineral having a superhard crystalline form. Depending on the impurities in its structure, it can take on a variety of colors: violet, green, yellow, orange or red.
The most valuable sapphire is blue, but the red crystal is already called ruby. In the manufacture of sapphire crystal, colorless (pure) stone is used.
Artificial crystal
Sapphires are mined in the same way as conventional fossil precious minerals. In the glasses of the same name, not intended for the manufacture of jewelry, natural stone is replaced with synthetic. At the beginning of the twentieth century, a chemist from France, Augustus Verneuil, brought out the world's first artificial sapphire crystal. The stone-making process he invented is used in our time. Alumina is heated to high temperatures and held for some time under high pressure.
Physical properties
Sapphire crystal is very durable and difficult to process; when cutting it, special diamond saws are used. According to the Mohs scale (the hardness of materials is estimated) sapphire crystal has 9 units, for comparison, tempered steel - 8 units. Also, this glass is almost impossible to scratch. Due to its properties, it has become widespread in everyday life and in industry.
