Garnet

DESCRIPTION:

The term "garnet" usually refers to a group of more than ten gemstones with the same chemical composition but different appearances. The most common color of this gemstone is red, although other colors are also found. This gorgeous deep red stone is mostly found in antique jewelry. It is sad to notice that we are unaware that the garnet world is more colorful than what we know. Though red is the principal color present in the stone, in countries like Africa, this stone is enhanced with other colors. The change of style and fashion in the jewelry world has given this gemstone a prominent place due to its spectacular colors. It keeps pace with the modern trends in the jewelry world. The strong resemblance of this stone to the seeds of a pomegranate is why it came to be called garnet.

The main feature that distinguishes this gorgeous gemstone from others is its hardness. Most of them, with few exceptions, have this hardness, and this important feature has made this sparkling stone occupy an important place in the world of jewelry. Another positive quality of this gem is its insensitivity, which makes it very easy to work with. It should not be knocked or exposed to overheating.

This sparkling gem was first discovered at the Kunene River on the border between Namibia and Angola. Until the discovery of this gemstone, collectors and lovers of gemstones rarely used this stone, but with its discovery, the entire gemstone world changed. It started to adorn jewelry, and later, with these stones being discovered in Nigeria, the demand for this stone shot up. Only an experienced gemologist could distinguish between stones from these two different countries.

The green variety of this precious stone is a gem that holds more importance than even a diamond. The only color not found among these stones is blue. This precious gem with numerous colors is not only used in jewels but also used to protect us and cure us from many diseases. This precious colorful gem is also considered a sacred stone by American Indians, African tribal elders, and the Mayans. The popularity of this stone is not limited to the jewelry world but also extends to its significance in the industrial market.

This sparkling gem, with its energizing and regenerating power, comes in several forms depending on the mineral base. The various types of garnets are Almandine, Andradite, Grossular, Pyrope, Spessartine, and Uvarovite. This long-lasting gem has occupied an important place in history. It is said that the hardness and durability of this precious gem came to light when it was found as beads in the necklace of a man in a grave thousands of years ago.

This sparkling gorgeous gem is one of the few untreated gems. It is often mistaken for other precious stones like ruby, topaz, and emerald. Though durable, it should be protected from damage and harsh temperatures, as well as other chemicals. This wonderful stone fascinates everybody with its rainbow of colors. With its durability, hardness, and wide range of colors, this beautiful stone will always remain a precious gem in the world of gems and jewelry.

FORMATION:

Garnets of various types are found in diverse geological settings worldwide. Most garnets originate from the metamorphism of sedimentary rocks rich in aluminum, such as shale. Under high temperatures and pressures, the chemical bonds within these rocks break down, leading to the recrystallization of minerals. Garnet, being more stable under these conditions, often forms as a result. This metamorphic process is typically associated with converging tectonic plates. Additionally, garnets can occur in igneous rocks like granite and basalt.

Due to its high resistance to abrasion and chemical weathering, garnet is commonly found in sedimentary rocks or highly weathered materials where only the toughest minerals remain, such as mineral sand dunes.

MINING:

Mining techniques for garnet extraction vary based on geological conditions. In hard-rock locations like the Barton mine in northern New York, open-pit methods have been the norm for decades. Conversely, in China, such sites often employ more basic methods such as manual mining.

Garnet extraction from alluvial deposits, like at Idaho's Emerald Creek mine, involves recovering garnet from stream gravels cut by backhoes or small draglines. These gravels undergo screening to remove oversize particles, with garnet concentrated using large wet-jigging tables. Subsequently, garnet is processed at the mill before packaging.

Beach deposits in Western Australia and southern India are mined economically using earth-moving techniques with scrapers and bulldozers to cut and excavate benches along the beach trends. In India, mechanized mining supplements manual labor, which remains integral to community responsibilities.

Processing generally includes separating heavier garnet from lighter gangue minerals and further classifying garnet into specific size ranges tailored to market demands. Crushing precedes washing to segregate materials by specific gravity, often utilizing spiral classifiers and hydrosizers. Some operations employ flotation for garnet separation from heavy, nonmagnetic fractions. Concentrates are dried and sorted using high-intensity magnetic and electrostatic separators.

For precision markets like grinding and polishing, one producer uses wet-separation techniques to ensure high-quality garnet, achieving over 95% garnet minerals with less than 0.5% quartz content by weight. Final production involves dry screening, classification into marketable sizes, and packaging for distribution.

PHYSICAL PROPERTIES:

Name : Garnet
Varieties : Almandine Garnet, Almandine-Pyrope, Rhodolite Garnet, Andradite, Demantoid Garnet, Melanite, Topazolite, Andradite-Grossular, Mali Garnet, Color Change Garnet, Gadolinium Gallium Garnet, Grossular Garnet, Hessonite, Hibschite, Hydrogrossular Garnet, Transvaal Jade, Tsavorite Garnet, Malaia Garnet (Malaya Garnet), Proteus, Pyrope Garnet, Chrome Pyrope, Pyrope-Spessartine, Umbalite, Spessartite Garnet, Mandarin Garnet, Uvarovite Garnet, Yttrium Aluminium Garnet
Colors : Generally brown, virtually all colors, blue very rare
Heat Sensitivity : depending on their specific type or variety
Formula : A3B2Si3O12. A = Fe, Ca, Mn, Mg. B = Al, Fe, Ti, Cr
Fracture : Conchoidal
Hardness : 6.5-7.5
Cleavage : None
Crystallography : Isometric Trapezohedron and dodecahedron forms are common. Cube and octahedron forms are extremely rare
Refractive Index : Varies by species, ranging from 1.72 to 1.95. See Gem Listings for specific varieties
Birefringence : None
Dispersion : Varies by species, ranging from 0.014 to 0.057. See Gem Listings for specific varieties
Luminescence : Most varieties are inert. Grossulars can exhibit a variety of fluorescence
Luminescence Present : Yes
Absorption Spectrum : See Gem Listings for specific varieties.
Pleochroism : None
Luster : Vitreous, inclining to resinous in grossular, andradite, and some almandines
Specific Gravity : 3.1–4.3
Transparency : Transparent to opaque
Birthstone : January