The garnet belongs to the silicates and germanates and is often used as a gemstone because of its attractive appearance. A garnet can have different colour tones, but is mostly reddish brown, yellow-greenish or even black. The gemstone has a fat, glass or resin gloss and can be both transparent and opaque. A characteristic feature of the mineral garnet is that its crystals are formed as rhombic dodecahedrons, i.e. as polyhedra with twelve rhombic surfaces. Garnets are opaque when foreign matter has settled in them. The variable colours of garnet are dominated by red, whereas blue has never been seen in such a mineral. The name of the garnet comes from Latin, where granum stands for grain or granatus was used for granular. The granular appearance of the garnet mineral shows a visual similarity to the seeds of the pomegranate, which is also often apt in terms of colouring. Even in ancient times, garnet was a popular gemstone, which, like ruby, was also known as carbuncle. The most frequent places of discovery for garnet are the USA, Sri Lanka and South Africa.