Almost all stones, including precious ones, are formed in the earth's crust due to complex processes over a long period of time. A certain mineral composition, high temperature and significant pressure can provoke the appearance of a diamond or form natural opal . But, the most important role in the formation of certain gemstones is played by the mineral composition. It is for this reason that deposits are formed only in certain regions of the earth's crust.
Minerals and Metals That Create Gems
In order for a blood-red ruby to appear, it is necessary that in the lava, molten rock there are several more elements in a strictly defined proportion. Aluminum, chromium and some oxygenated air bubbles. Since the combination is not always achieved in the right amount, ruby is quite a rare stone that can be found in nature. Other gems are formed in a similar way:
- Diamonds are composed entirely of carbon, which changes under the influence of high temperature and pressure in the bowels of the earth.
- Turquoise is nothing more than a complex alloy of oxides of aluminum, phosphorus and copper.
- Chrysolite is obtained in igneous rock by mixing silica, magnesium and iron.
- Alexandrite, a very rare gemstone, is prized for its unusual colors.
- Jadeite fascinates with its crystalline structure formed by iron, sodium, silicon, aluminum and oxygen.
Important: some of the precious stones are formed not in the earth's crust, under the influence of pressure and high temperature, but in sedimentary rocks. They form the longest, it takes several tens of millennia.
Durability of Gems
Since most of them formed deep underground at high temperatures and pressures, it is not surprising that they have a fracture-resistant structure. There is a table of hardness according to Mohs, according to which all precious stones are distributed. The most popular and demanded will look like this:
- diamond, record holder in strength;
- ruby and sapphire are not much inferior;
- alexandrite is difficult to damage;
- ceylonite, a rare stone;
- topaz, often seen as a decoration.
Morganite stone with a precious component was discovered relatively recently. The sufficiently high strength of 7.5 made it possible to use it in jewelry. Has shades of pink, red and yellow. Rare enough to be found only in nature.
