Garnet: description, properties and photo
Garnets are a group of minerals with the same structure, but different chemical composition. Properties of the stone may also have differences due to its composition. For example, we can observe the various color of the mineral: red, orange, yellow, brown, green, yellowish green, pink, colorless, black and also with the color change effect. The name of the mineral comes from the latin “granatum” – the fruit of pomegranate, due to the similarity of the shape and the color of crystals with fruit grains. It is worth noting the physical properties of the stone: in addition to the variety of colors, its high hardness, excellent luster and strong dispersion.
Consider the properties and characteristics (descriptions) of garnets varieties. Two subgroups are distinguished in the mineral group depending on the chemical composition: pyralspites (mineral species: pyrope, almandine, spessartine); and ugrandites (mineral species: uvarovite, grossular and andradite). The composition may also be intermediate between its mineral species. The following are descriptions of the varieties of garnet with an indication of the characteristic color palette for each species.
Pyrope garnet colors: fiery red to dark red, sometimes brownish red. The name of the mineral comes from the greek “pyropos” is «fire». Pyropes are garnets, which are found in usually rounded grains, not crystals. In jewelry it is usually represented by small stones of a dark color. The cost of the pyrope mineral is about thirty dollars per carat. Go to pyrope encyclopedia.
Almandine is the most common species. Description of the color of almandine: red with a purple tint, less often deep red and dark brown. The name of the mineral is associated with Alabanda, a city in Asia Minor. Almandine is an inexpensive stone. Its cost is tens of dollars per carat. Good quality stones are more expensive than pyrope. Go to the Almandine Encyclopedia
Rhodolite is a commercial variety of garnet, intermediate in composition between pyrope and almandine. The name comes from the greek “rhodos” (rose) and “lithos” (stone). Color characteristic of rhodolite: from pink to pinkish red, violet red. The cost of rhodolite usually does not exceed $ 250 per carat, but occasionally there are very bright specimens with a cost of more than $ 1,000 per carat. Go to the Rhodolite encyclopedia
Spessartine is less common than pyrope, almandine and rhodolite. Description of the color of spessartine garnet: orange, orangy red, brownish red, yellow. The name of this stone is given in honor of the Spessart Mountains in Germany, where it was first discovered. The cost of high quality spessartine can be more than $ 1,000 per carat. Go to Spessartine Encyclopedia
Malaya is a gemstone of pinkish-orange, reddish-orange or yellowish-orange color. It’s the most valuable variety of garnet. It has composition between pyrope and spessartine by chemical composition. Malaya garnet can sometimes have a color change effect. This is a very rare stone.
Uvarovit is a bright green stone. It presents in the form of small opaque crystals (usually up to 2-3 mm). This garnet will be named after the president of the Russian Academy of Sciences, collector of minerals S.S. Uvarov (1786-1855). The main uvarovite deposit is Saranovskoye in the Urals. There are also large size uvarovites in Finland- more than 1 cm across.
Grossular is a type of garnet mineral. Its classic color is green. From the latin language “grossularia” means “gooseberry”. The color in grossulars also can be green, yellowish-green, orange, yellow, pink, colorless. The price of green grossulars, for example, tsavorite and “mint garnet” can reach several thousand dollars per carat.
Tsavorite – garnet usually with saturated green color, a kind of grossular. Tsavorites got their name in honor of the place of the first find – Tsavo National Park in Kenya. The color of the tsavorite is similar to emerald, but in its rarity tsavorites exceed emeralds by about 300 times. Tsavorite is one of the most expensive garnets. Its cost can be measured in thousands of dollars per carat. Go to the tsavorite encyclopedia
Grossulars can be called mint garnet in trade because of their typical light green and light yellowish-green color. Sometimes such garnets are sold under the name «tsavorite». There is no clear distinction between these varieties on the market.
Hessonite is a garnet variety of orange, yellow-brown, orange-red and brown-red. The name of the stone comes from the Greek word “hesson” – inferior. This is due to the fact that it was originally considered to be hyacinth (a kind of zircon), only with less hardness. Hessonite usually does not exceed $ 250 per carat.
Andradit is a garnet named after the Brazilian mineralogist J. B. d’Andrada, who first described the mineral in 1800. There are several varieties of andradite:
- Andradite, which has reddish brown color. It’s the most common type, rarely applied in jewelry.
- Topazolite is a yellow, yellowish brown gemstone. It is usually found in deposits along with another kind of andradite – demantoid.
- Demantoid is a very rare and most expensive variety of garnet. The name of the stone “demantoid” can be translated as “similar to a diamond.” The comparison with diamond is due to the fact that the play of color flashes in faceted demantoids is even more than in diamonds. Since the dispersion property of the demantoid (0.057) is higher than that of diamond (0.042). The color of the demantoid garnet is green, often with yellowish or brownish hues, rarely with a blue tint. For the first time, demantoids were found in the middle of the 19th century in Russia, in the Urals. The price of large high-quality Ural demantoids in the world market may exceed $ 10,000 per carat. The demantoid from the Urals is characterized by fine-fiber inclusions of byssolite called “horse tail”. Go to the demantoid encyclopedia.
The most valuable garnets are demantoid, tsavorite and spessartine. Garnets with color-changing properties are also very highly regarded. Their cost may exceed $ 1,000 per carat.
Pyropes were previously mined in Bohemia in the Czech Republic. Mines are also in South Africa and the United States. Gem quality almandines are found in India, Sri Lanka, Madagascar, Brazil, USA and Pakistan. Rhodolite is mainly mined in Sri Lanka, Tanzania and Madagascar. Spessartine deposits are known in Namibia, Nigeria and Mozambique. Spessartines are also produced in small quantities in Brazil, Myanmar, Madagascar, Tanzania, Sri Lanka, and the United States. Malaya garnet is mined in Kenya and Tanzania. Grossular deposits are known in Canada, Mexico, Brazil, Italy, Finland and Azerbaijan. Tsavorite is mined in Kenya, Tanzania and Madagascar. Hessonite is mined in Tanzania, in alluvial deposits of Sri Lanka and India, Madagascar, Mexico, Canada, small amount mined in US deposits. Uvarovite is mined in Russia in the Urals, in Finland, Kazakhstan and South Africa. Topazolites are mined in the Urals, in Italy, in the USA (New Jersey). In addition to the Urals, gem-grade demantoids enter the world market mainly from Namibia and Madagascar. Demantoids are also found in small amounts in Iran, Pakistan and Italy.