Grenades are a large group of similar stones, which some classify as ornamental, others to the noble ones. Chemically, they belong to the silicates in the general formula M.3R2 (SiO4)3. Interesting real construction

Rubin i szafir

Rubin i szafir – Korund.

Transparent types of corundum are precious gemstones, have been used for ornamental purposes for a very long time. The red variety is called ruby, blue or other - sapphire. Fine crystalline, compact, granular varieties of corundum are used for the purpose …

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).

A very large factor …