The history of garnet dates back to the Bronze Age (more than 5000 years ago), when it was a very popular gemstone. Garnet is a family of minerals that have similar crystalline and physical properties. Garnet is found in a wide variety of metamorphic rocks and in some igneous rocks. Garnet is one of the most common nesosilicates but it has a complex structure. The formula for garnet is (Mg, Fe, Ca or Mn) with Al2Si3O12. Garnet is very common on gneiss and mica slate. Garnet is a very abundant gem and can be easily found in many parts of the world. Garnet crystallizes into rhombic dodecahedra and trapezohedra. Garnet is a natural abrasive that is still commonly used in woodworking. The name garnet is derived from the Greek word “granatum” or pomegranate seed. One of the oldest gemstones in history, garnet is the birthstone for January.
Garnet is a gemstone that comes in a wide range of colors. A popular garnet is chrome pyrope, whose color rivals ruby. Pyrope garnet is the familiar dark red garnet. Garnet is also found in colors ranging from green to orange, brown, and black. Almandine garnet is the traditional Indian garnet, which is very dark purplish red in color. Andradite garnet is usually black and is of no interest to the gem trade, but a variety called “Demantoid” is bright green. Yellowish green or Val Malenco garnet is typical of Fe3 +. One of the most sought after varieties of gem garnet is the fine green coarse garnet from Kenya and Tanzania called tsavorite. Mozambique Rhodolite Garnet is an elite garnet that cuts a brilliant red with fiery sparkles. Hessonite garnet is a genuine garnet, but with a reddish-brown or orange color. Malaya garnet is generally found between Kenya and Tanzania, especially around the Umba Valley region, which is well known for its buried treasures. Mandarin garnet is an extreme rarity of the spesartin family.
Almandine is the most common garnet and the most widely used garnet gem. Almandin, Fe3Al2 (SiO4) 3 (iron and aluminum silicate), is a mineral of the garnet family of tetrahedral silicates. The almandine garnet is a deep red, soft and transparent stone that owes its color to the presence of iron. Connecticut is one of the world’s best sources of the almandine garnet, named a state mineral by the 1977 General Assembly. Although almandine garnets (also known as “almandite”) are the most common variety of garnets, those that show the star do not they are not at all common. Most almandine garnets are mined in India and Brazil. Iron-rich almandine is widespread in metamorphic rocks such as schists and gneisses and in granitic igneous rocks.
Pyrope is the only garnet that always has a shade of red. Pure pyrope is extremely rare and would be colorless (it is allochromatic); Most of the red gem garnet called pyrope contains an appreciable almandine component. This pyrope is one of the most highly valued so-called “indicator minerals” in diamond prospecting. Pyrope is commonly purplish-red, orange-red, crimson, or dark red; and almandine is dark red, brownish-red, brownish-black, or violet-red in color. It was the pyrope garnet that figured in ancient Talmudic legend, which held that the only light in Noah’s ark was supplied by a huge red garnet. The Czech Republic is one of the few places where the Pyrope garnet variety is found.