Definition
Mohs scale hardness 6.5 to 7.5
Many hues of garnet species can be found, although reddish tones are the most prevalent. The rarest garnets are blue, and reports of them date back to the 1990s. a specimen displaying the dark red hue that garnet is capable of. The transparency of garnet species can range from translucent specimens suitable for use as gemstones to opaque variations utilized as abrasives in industry. There are two types of mineral luster: vitreous and resinous.
Since the Bronze Era, garnets, a group of silicate minerals, have been utilized as abrasives and jewels. Garnet species vary in chemical makeup but have comparable physical characteristics and crystal structures. The many species include pyrope, almandine, spessartine, grossular (varieties of which include tsavorite and hessonite or cinnamon-stone), uvarovite, andradite.
The atomic bonds in certain species of garnet are stronger than in other species because garnet's chemical makeup varies. Because of this, the hardness range for this mineral group on the Mohs scale is around 6.0 to 7.5. Abrasive uses frequently include the tougher species, such as almandine.
For gem identification reasons, garnet is distinguished from all other naturally transparent gemstones frequently used in the jewelry industry by a pick-up reaction to a strong neodymium magnet. The distinction between garnet species and variations, as well as the composition of garnets in terms of the proportions of end-member species within a single gem, may be made using magnetic susceptibility measurements in combination with refractive index.
Varieties of Garnet
Topazolite
Topazolite is a yellow or brownish-colored andradite garnet. It resembles Topaz in appearance, and this similarity is what gave it its name. Stones of class II clarity are andradite garnets. Stones with low mohs hardness may have surface scratches or abrasions.
Melanite Garnet
Melanite is an incredibly uncommon opaque jet-black andradite garnet type. When faceted, this gem's great brilliance gives the stone the appearance of being made of black glass. Victorian mourning jewelry featured a lot of melanite.
Malaia or Malaya Garnet
This red-orange to pink-orange form of garnet was initially believed to be spessartite garnet when it was found in Tanzania's Umba Valley in the middle of the 1960s. Malaia garnets, which are bright jewels with flashing red flashes, are actually a blend of pyrope and spessartite. As soon as it was determined that it wasn't spessartite, it was referred to as malaia, a Swahili word that means "out of the family." Malaia garnets come in a wide spectrum of orange tones, from delicate peach to vibrant reddish orange. Stones with class II clarity include malaia garnet. Some stones include crossing needles and mineral inclusions including pyrite, apatite, and rutile.
Hydrogrossular Garnet
Usually accessible as cabochons, hydrogrossular garnet is translucent to opaque but can occasionally be found as transparent, faceted gemstones. This gemstone, which is typically observed as green to blue-green, pink, white, and gray, may also contain microscopic dark gray to black inclusions and, if opaque, may resemble jade. A form of grossular garnet known as hydrogrossular occurs when hydroxide partly replaces silica. perhaps pepper-like black magnetite inclusions.
Andradite Garnet
The andradite garnet belongs to the ugrandite garnet family. Andradite garnet comes in a variety of forms, including demantoid, melanite, rainbow andradite, and topazolite. The stones might be black, grayish black, brown, reddish-brown, yellow, and green. It bears the name José B. de Andrada e Silva, a geologist from Brazil. Amazing gems made of andradite have more color dispersion than diamond. Stones of class II clarity are andradite garnets. Stones with low mohs hardness may have surface scratches or abrasions.
Almandine Garnet
Garnet is an entire category of minerals that range in their chemical makeup, resulting in a variety of gems exhibiting distinct hues and qualities. They all have the same cubic crystal structure (like spinel and diamond), but they do not all have the same cubic crystal structure. Other garnets, such as orange spessartine, green demantoid, and tsavorite, are far less frequent, despite the fact that some kinds of red garnet are widespread and may be found on almost every continent. There are more than 20 different types of garnet, but the five most significant are andradite (which contains demantoid), spessartine, which includes hessonite and tsavorite, and pyrope and almandine (which when combined make rhodolite). Type II clarity describes almandine garnet. Stones frequently have needles that connect at angles between 70 and 110 degrees. Zircon crystals often exhibit strain haloes. There are other crystals that are irregular or rounded.
The birthstone for January is the garnet, thus January infants aren't just born with the well-known red variations.
Pyrope Garnet
When people hear the term "garnet," they immediately think of the deep red pyrope garnets of the pyralspites family. Pyrope is derived from the Greek words pyr and ops, both of which imply "fire eye." Pyrope is usually always red but can sometimes be purplish red. Anthill and chromium garnet are the names given to Arizona stones.
Needle-shaped inclusions and uneven, spherical crystals of apatite or zircon.
Umbalite Garnet
Umbalite is another name for Malaya (Malaia) garnet. Umbalite is a new garnet component. It was discovered in the 1960s, mixed together with parcels of rhodolite garnets from the East African Umba River Valley. Because the substance was first rejected by many consumers, local miners and traders gave it the Swahili term "Malaya," which translates to "out of the family." Testing revealed that the new gem was a combination of pyrope and spessartite garnet. Its vibrant colors range from pale pinkish to dark pinkish, red, and yellowish orange. Umbalite is one of the most costly garnets, with only Kenya and Tanzania as recognized sources. Apatite, graphite, rutile crystals and needles, sulfides, fingerprint-like inclusions, growth tubes, and negative crystals are all common.
Spessartine Garnet
Spessartine, an orange form of garnet, was previously considered a collector's gem until fresh resources in Africa were found in the 1990s, catapulting it into the mainstream. Spessartine, like other garnets, is normally untreated, so the exquisite color and purity that you see in them is just as nature intended. Spessartine garnet was called after its discovery at Spessart, Bavaria, in the mid-nineteenth century. Spessartine garnet is a stone of category II clarity. Stones may include feathery 2-phase liquid inclusions as well as rutile needle inclusions.
Spessartine-Pyrope Garnet
Garnet stones are frequently a combination of garnet species. Spessartine-Pyrope stones are mostly made up of these two minerals, with tiny quantities of almandine and grossularite thrown in for good measure. Light to dark, somewhat pinkish orange, reddish orange, yellowish orange, blue, teal, greenish blue, pink, red, and purple stones are available. Color alteration or color shift phenomena are common in stones. The stones are also known as "Malaya" garnet. Pyrope-spessartite is a stone of category II clarity. Mineral inclusions like as rutile, apatite, and pyrite can be found in stones, as well as intersecting needles.
Pyrope-Almandine Garnet
Garnet stones are frequently a combination of garnet species. Pyrope-Almandine stones are generally made up of these two garnet types. Rhodolite is the name given to pyrope-almandine stones that include a purple component. Stones can range from orange red to brownish red and dark red, as well as light to dark purplish red to reddish purple. Pyrope-almandite garnet is a stone of grade II clarity. Needle-like inclusions, stain-haloed zircon crystals, and irregular spherical included crystals that might be zircon or apatite.
Uvarovite
Uvarovite is a highly sought-after but relatively unknown garnet species. It was called after Count Sergey S. Uvarov, a 19th century Russian nobleman, scholar, and passionate mineral collector, who discovered it in the 1830s in Russia. Uvarovite is highly sought after by collectors and is difficult to come by, especially in sizes larger than 0.25 carats. Uvarovite is a medium to dark green mineral that is most recognized for its granular, drusy masses that show well-formed dodecahedral or trapezohedral crystals when magnified.
Grossularite
The earliest grossular garnet specimens discovered were pale green and looked like gooseberries. The name of this garnet species comes from the Latin word for gooseberry, "Grossularia". Grossular garnets are not completely green. The variety names for most grossular garnets include hessonite, tsavorite, mint, leuco garnet, and hydrogrossular.
Rosolite, Landerite or Xalostocite
Rosolite, also known as landerite or xalostocite, is discovered in Sierra de Cruces, Mexico. It is a transparent to opaque form of grossular garnet that can be found in marble.
Hessonite Garnet
Hessonite, sometimes known as the "cinnamon stone," is a kind of grossular garnet that appears in two colors: golden and cinnamon. A perfectly colored hessonite is a vivid golden orange with an interior fire that resembles a blend of honey and orange. Some hessonites have red and brown tones with a cinnamon look. Hessonite is widespread in the gem gravels of Sri Lanka, and almost all hessonite comes from there, while it is also found in Africa. While the purest diamonds are the most valuable, hessonite inclusions are frequent, with peculiar toffee-like streaks giving hessonite an oily or even glass-like look. Crystals that were stubby and rounded were included. The greasy, "wave" or "wiskey in water" effect is seen.
Tsavorite Garnet
Tsavorite is one of two green garnet types, possibly the most significant. Tsavorite competes with emerald, particularly in smaller sizes, since it is less included, seldom treated, and more durable. Tsavorite garnet, like some emerald and green tourmaline, gets its green colours from the presence of vanadium and chromium. Tsavorite is named after the adjacent Tsavo National Park, which was found in Tanzania in 1967 and Kenya a few years later.
Tsavorite garnet is a stone of Type II clarity. Feathers, fingerprint inclusions, needles, asbestos particles, and microscopic graphite platelets are all common in stones.
Mali Garnet
Grossularite-andradite garnet is Mali garnet. It is occasionally marketed as grandite. Mali garnets range in color from pale greenish yellow to dark orangy brown. Many Mali garnet stones are inclusion-free, however tiny mineral crystals and fingerprints are occasionally seen along with parallel development planes
Demantoid Garnet
Demantoid garnet is one of the most sought-after and unusual colored gemstones. The name demantoid comes from the ancient German word demant, which means "diamond-like," because of its brightness and dispersion, which provides a fire even greater than diamonds. Demantoid garnet is a stone of grade II clarity. Stones may have surface abrasions. Fibrous chysotile asbestos or "horsetail inclusions" may be found in certain stones. Namibian stones may exhibit stress fractures.
Cat's-Eye and Star Garnet
Garnets with an asterism are known as "star garnets." Depending on how you hold the stone, you'll see this as a star-like reflection of light that moves around the object. Almandine and pyrope-almandine species can both experience this asterism. To best display their characteristics, star garnets are carved into cabochons. The majority of specimens contain stars with four rays, while six rays are quite uncommon. Only Idaho in the United States and India are home to commercially available star garnets.
Origins
There are garnets all throughout the planet. Garnets come in many distinct varieties, and each kind may be found in various places. Pyrope is found in South Africa, Sri Lanka, China, and Madagascar, whereas almandite is native to India, Brazil, and the United States.