Garnet is an interesting and universal stone. The word “garnet” usually associates with the dark red stone, presented on the market. Recent openings show, that garnets are in different colours and cost very expensively.
Pirop has a blood-red colour. There are not many inclusions in it. High-quality pirops in a considerable quantity were extracted from the diamond tubes of Kimberley and De Bierce in Southern Africa.
Almandine. The colour of this stone varies from dark red to violet-red or even black. Cabochons are often made bent from the bottom side that more light could get into a stone.
Shpessartite has a rich orange-red colour and similar to feathers or laces inclusions which actually are the “clouds” of the smallest drops. It has an excellent shine, but a “pure” qualitative precious material is found seldom.
Shpessartite-tangerine is a garnet version, the pure shpessartite kind from Namibia. It has the most fantastic bright orange colour. Tangerine garnet of jewellery quality is very rare and valuable.
Hydrogrossulyar has an excellent gooseberry-green colour. This stone is translucent and opaque. It is cut in a form of cabochons or beads. Sometimes pink hydrogrossulyar is found.
Rhodolite has a beautiful bright violet-red colour with small amount of inclusions. On structure it represents something average between pirop and almandine, but it has a brighter colour than pirop, and it has fewer inclusions than almandine. The stones of high quality are found in Sri Lanka, Tanzania and Kenya.
Hessonite. In Africa for orange-brown or yellowy-brown colour this stone is called a cinnamon stone. The stone has an excellent vortical, similar to the treacle inclusions which are the small crystals of apatite.
Cavorite – is a transparent kind of hydrogrossulyar, with coloring from lime-green to emerald-green. It is almost always a facet grinding gem. As a result, the stones of emerald-green colour are more expensive, than lime-green. Cavorite has a strong shine and inclusions becoming golden-yellow needles, tubes of corrosion and black flakes of graphite.
Grossulyar-malaj. Jewellery quality grossulyar has been found in Mali rather recently. The colour of the stones varies from the golden-brown colour to apricot, yellow and peach, pink, and sometimes green. This stone is also named Malian garnet.
Demantoid – is the name of the bright green group of garnets, called andradites. They are very rare and they are seldom more than 1 carat. The stones are extracted in the Urals Mountains (Russia). Demantoid has a higher dispersion of light and sparkling than brilliant, therefore brightly “plays”. However, the aspect sides can grind off, as the stone hardness is only 6,5 on Moos scale. Demantoid has the inclusions of yellowy-brown colour in the form of “a horse tail» and the inclusions of asbestos similar to the hair. It is the most valuable kind of a garnet.
The changing colour garnet. These garnets can be green-dark blue at day light and purple-red at artificial light. Other stones change the colour from red-violet to yellow-red. They are a mix of pirop and shpessartite and meet very seldom.
Estimation of garnet
The garnet has a high density, therefore a stone is rather heavy. It leads to that it is a little bit more expensive than other gems of the same size. Many badly know cavorite, demantoid, tangerine garnet and changing colour garnet. Unlike pirop and almandine, these stones are extremely valuable and can be used for expensive jewellery. Rhodolite and shpessartine have the average cost for garnets. They have more intensive colours, and they are appreciated above than pirop and hessonite.
Hardness 6,5 – 7,5 on Moos scale
Density from 3,49 to 4,16
Factor of refraction from 1,69 to 1,89
Crystal lattice: garnets are a group of structurally and chemically connected minerals, crystallized in cubic system; also there are spherical crystals. The garnet has a glassy shine. It is possible to find garnet with a star, having red and violet colours, with weak 4 or 6 beam stars which are less expressed than in corundum.
Deposits of garnets: Argentina, Brazil, Germany, India, Madagascar, Mali, Namibia, Pakistan, Russia, Scandinavia, Southern Africa, Sri Lanka, Switzerland, Tanzania.