Diamond imitations

Diamond imitations

Apart from the primitive way of imitating diamonds with varieties of glass with a high refractive index, colorless sapphires are used to imitate this most valued gemstone., zircons or topazes, sometimes also transparent quartz (Mountain crystal).

The diamond's very high refractive index allows it to be quickly recognized and distinguished from other stones. One of the simple ways to distinguish a real diamond from imitations made of glass or other stones is to immerse the test stone in a liquid with a specific refractive index. If e.g.. dip a piece of glass in a salt solution of the same refractive index, it becomes invisible, when the diamond in such a liquid shows dark outlines. The table shows the most important properties of the diamond and its imitations.

Properties of a diamond and its imitations
Stone Mohs hardness Density in g / cm3 Factor








Diament 10 3,52 2,41 0,044
Zirconium 7,5 4,39 1,926-1,985 0,059 0,039
Synthetic rutile 6,5 4,25 2,61-2,90 0,287 0,300
Korund 9 3,99 1,760-1,768 0,003 0,018
Synthetic spinel 8 3,63 1,727 0,020
Topaz 8 3,56 1,612-1,622 0,910 0,014
Quartz 7 2,65 1,544-1,533 0,009 0,013
Glass (special species) 5 3,74 1,635 0.031

Most often, zirconium is used as a diamond imitation, which has a relatively high refractive index and a dispersion similar to that of a diamond. However, the distinction between these two minerals is not too difficult. It is enough to examine birefringence, which is distinct in the rhinestones and which the diamond lacks. These stones can also be distinguished this way, that they are placed in a flat dish filled with methylene iodide and lit from below. This examination is usually performed under a microscope. The diamond appears completely black due to the total reflection of the light, inside the zirconium there is a bright field, surrounded by a black ring.

Synthetic rutile, whose refractive index is even higher than that of a diamond, can be distinguished by different dispersion; the light scattering in rutile has an opal character, rainbow color variation. Colorless corundum differs from diamond by a double refraction, very poor dispersion, and in methylene iodide it is completely transparent. These differences are evident in the case of other diamond imitating stones.

Diamond imitations made of special types of lead glass (rhinestones), having a high refractive index, they are easy to distinguish due to the low hardness of the glass and a much lower refractive index.

Diamonds are sometimes called well-educated, transparent quartz crystals (rock crystal) high gloss on natural walls, e.g.. mexican diamonds, diamonds from Alaska (Alaska diamond), z Arkansas, z Alencon. Similarly, incorrect trade names are sometimes used to describe quartz, like Czech or German diamond etc.. The Marmarosh diamonds are tiny quartz crystals found in the Eastern Carpathians. The name Matara or Matura diamond is sometimes used to describe a colorless zircon, and the name of the Saxon diamond - colorless topaz.