How to grow a ruby?

Ruby and sapphire refer to the most expensive and most beautiful of precious stones. They have long been sung by poets, legends and tales have been telling about them from time immemorial, they have long been selling them and fighting because of them. An ancient Indian legend tells that a red, semi-precious stone ruby was born from drops of blood of the good god Assur: an evil demon of Lanka flew to Assyria in the air, furiously tormented him, and drops of blood fell into the dark waters of the river... They fell and stiffened in precious rubies...

How to grow a ruby, and what kind of stone in terms of science?

The scarlet ruby (fig. 1) in antiquity and in the Middle Ages was very appreciated and considered a healing stone: "ruby heals the heart, brain, strength and memory of a person". This love of a stone is by no means a thing of the past. And now people love jewelry made of semi-precious stones. A ring with a ruby, ruby brooches or earrings - is not uncommon, they can be bought at any jewelry store. What's the matter? It's just that people have learned to grow precious crystals of rubies. But, artificial crystals of ruby were needed not only for ornaments. How to grow a ruby, and what kind of stone in terms of science?

The mineralologist will say: ruby and sapphire are siblings, it is generally the same mineral - corundum, aluminum oxide Al2O3. The difference in color is due to very small impurities in aluminum oxide: an insignificant addition of chromium turns colorless corundum into a blood-red ruby, titanium oxide into sapphire. Corundum with all its varieties is one of the hardest stones on Earth, the hardest after diamond. Corundum can be drilled, polished, polished, sharpened stone and metal. In addition, ruby has become the main material for laser and laser beam went out into the open spaces of the universe. All this because the ruby crystal can amplify the light.

The laser beam has a tremendous power. It easily burns sheet metal, welds metal wires, sews metal pipes, drills the finest holes in hard alloys, diamond.

So, do not get distracted! How, after all, to grow a ruby? Grow crystals ruby is difficult because it has an unusually high melting point: 20300 C. For the first time, the French scientist Verneuil grew ruby crystals in the very beginning of the 20th century.

The advantage of Verneuil's method lies in the fact that the crystal grows from the melt, but without any crucible, for ruby crystals grow like stalagmites in the cave (fig. 2): fine powder, fine powder, aluminum oxide is poured by a continuous thin trickle and falls into the flames of explosive gas, where the temperature is more than two thousand degrees, so that the powder immediately melts. The smallest droplets of melt fall down on the stand, on which the crystalline-seed is already fixed, and, solidifying, crystallize. So the crystal grows.

Artificial stone is not only not worse than natural: the same color, the same paint game, the same hardness, the same brilliance. But he is better than natural. Natural crystals of gems are small. A natural ruby weighing two or three grams is already the greatest rarity and preciousness, while in the laboratories and in factories rubies up to a meter long weighing in kilograms are raised!