The first synthetic rubies were produced at the end of the 19th century in France. Currently, a large number of synthetic rubies obtained by various methods are on the market. Synthetic rubies in hardness and their physical characteristics fully correspond to natural stones. They have the same hardness, refractive index, gloss. They are simply grown in a laboratory or in a factory in a short time. Why do natural rubies cost hundreds of times more than synthetic ones? Because they are rare, and there are very few deposits in the world where you can find pure, beautiful ruby. And synthetic ones can be produced a lot, and they are available to everyone.
Only a highly qualified specialist can distinguish a natural ruby from a synthetic analog when studying a stone under a microscope. In natural rubies, you can see inclusions similar to silk or rectilinear zoning of color. Since synthetic crystals are grown very quickly, apart from inclusions and clots of dye (aluminum oxide) and a cloudy whitish veil, nothing can be seen in them.
Identification is made by the internal features of inclusions and internal defects, increasing from 20 to 50 times. When diagnosing natural rubies and their differences from synthetic ones. It is recommended to remember the following rules: pure densely colored rubies of large sizes are scarce in nature. Natural rubies almost always contain inclusions and cracks. But it should always be borne in mind that a bright red ruby, without damages weighing about 1 carat and above, is very rare.
In the photo above, inclusions of rutile crystals in natural ruby (Thailand deposit), and the image on the right is a natural ruby crystal in the rock.
The photo below shows synthetic rubies. The raw materials of synthetic rubies and the stone are obtained from this raw material. Characteristic whitish veil-like inclusions in synthetic ruby.