Garnets consist of a complex range of varieties of similar chemical composition and come in a great range of colours. Since Victorian times the garnet normally met with was the deep red, ruby-like stone, but today there is a very wide selection of colours from which to choose.
They all have certain properties in common; namely ,they are all members of the cubic crystal form and therefore are all singly refractive, with a hardness between 6.6 and 7.5 The simplest way to classify the very many types is to list them in the various colour groups.
COLOR,CLARITY & CUT
Garnet is not one mineral, but recount a group of several closely minerals. The gem come in a variety of colors and have many different varieties. The most widely-known color of Garnet is dark red .
Red-sometimes called ‘carbuncles’ in the past when cut as recess backed cabochons. The most prominent of the red garnets is the fiery pyrope usually in small sizes. Almandine is also a red ,but is available in larger stones and other colours. Mozambique Garnet is a deep red and a mix of a pyrope and almandine.
Rhodolite is a more violet red. Garnet can be found in orange, green, purple, blue, yellow –brownish colours.
Colour change Garnets – As with several other gemstones, Garnet has varieties that change colour or shade under different lighting conditions tungsten and daylight. A ‘rainbow Garnet’ has been discovered in Japan that shows iridescent colours reminiscent of Labradorite – The most expensive Garnet come in a green color, called Demantoid.
While the color of demantoid never equals that of the finest Emerald, an Emerald-green is the ideal. The color should be as intense as possible, without being overly dark or yellowish green. The color of demantoid is believed to be due to chromium. It should be noted that demantoid’s fire is best seen in the lighter, less saturate gems. Thus the color preference is a matter of individual taste. Some people will choose an intense body color and less fire, while others prefer a lighter body color and more fire.
In terms of clarity, demantoid is relatively clean. Thus when buying one should expect eye-clean or near-eye-clean stones. Demantoids often contain radiating needle inclusions that are termed “horsetails.” In the market, demantoids are found mainly as round brilliant or cushion cuts. Cabochon-cut demantoids are not often seen.
SPHENE GEMSTONE PROPERTIES:
|Chemical Formula:||CaTiSiO5 Calcium titanium silicate|
|Crystal Structure:||Monoclinic; platy|
|Colour:||Yellow, brown, green, reddish|
|Hardness:||5 to 5.5 on the Mohs scale|
|Refractive Index:||1.843 to 2.110|
|Density:||3.52 to 3.54|
|Transparency:||Transparent to opaque|
|Double Refraction or Birefringence:||0.100 to 0.192|
Demantoid is among the most expensive of all Garnets, with prices similar to those fetched by fine Tsavorite (the other green garnet). But like all gem materials, low-quality (i.e., non-gem quality) pieces may be available for a few dollars per carat. Such stones are generally not clean enough to facet. Prices for Demantoid vary greatly according to size and quality. At the top retail end, they may reach as much as US$10,000 per carat. Visit our dubai online shopping and we can assist you with the right information about the value of Garnet and about any other gold stones.
ORIGINS & IMITATION
A variety called “Raspberry Rhodolite “was discovered in 1987 in Tanzania, “Cherry Rhodolite” is found in the same area. “Cranberry Rhodolite”, a pinkish red, has been discovered in Nigeria. Another pinkish –red Garnet-known to the trade as “Grape Garnet” has been found in India, Tanzania, Madagascar and South America. Deep red garnet with orange flashes from Tanzania has been marketed as “Crimson Garnet”. Yellowish-orange to brownish-red- Hessonite falls into this group and is sometimes called “Cinnamon Stone”
Spessartine (Spessartite) is an orangey red. An impressive variety of the group was found in Namibia few years ago and was christened ‘Mandarin Garnet”. A similar find was subsequently made in Nigeria. This is one of the more pricey garnets.
Some examples of Andradite Garnet also fit into this colour range but is better known for other colours. Grossular Garnet from Tanzania provides us with ‘Tangerine Garnet’, a bright orange.
Malayan or Malaia Garnet is a cross between spessatine and pyrope, giving a yellowish-brown to brownish –pink hue; the more pink the tone, the more expensive the stone . Shades from Madagascar are sometimes termed ‘Imperial Malaia’ or ‘Champagne Garnet’.
Yellow- Topazolite is lemon to lemon –yellow from the grossular group and has been found in Switzerland, the Italian Alps and California,USA.
Green – These will either be Demantoid, Tsavorite or Mali Garnet :the most famous and very expensive is Demantoid. Regularly used by Fabergein some of his fabulous designs. This beautiful stone has a greater fire than diamond but is only 6.5 on the Mohs scale. It is a variety of Andradite and has an admantine luster, like Diamond. It is found in the Urals and Zimbabwe. The Russian stones sometimes contain a diagnostic inclusion called a ‘horse-tail’.
Tsavorite, a beautiful green, is less expensive than Demantoid and Emerald and was discovered in 1967 in Kenya. The most popular shade is termed ‘Forest Green. It is not as yet treated. A lighter shade of this stone was discovered in the Tanzanite mines and is traded as Meralani. The Mali Garnet was discovered in 1994 in the Republic of Mali in West Africa. Yellow-green, honey-green and chartreuse shades are available, and a chrome variety has also been reported. Another green Garnet, the Uvarovite, occurs only in very small stones and is therefore little used. A colour change variety from East Africa also occurs.
Blue – A colour that is rare in Pyralspite Garnets but has been found in Madagascar. This also tends to show a colour change to mauve in incandescent light.
Black – Melanite of the Andradite group of garnets is black and, with the increased popularity of black gemstones, is taking its place alongside diamond, onyx, etc .in the world of fashion.
Garnet-toppped doublets, and triplets used to be common. Almandine Garnet was commonly used as the top stone in doublets with the lower section being coloured glass. They were used to imitate various gemstones such as Emerald, Ruby, Sapphire, Topaz, Amethyst & Peridot, the colour of the glass determining the type of gem. When combined with a bezel or gypsy setting they can be difficult to identify. Unset the junction may be seen by immersing in water or immersion fluid, if available.
Star garnets – Idaho in the USA is one of the few places to produce these. Mainly translucent purplish –red stones but some transparent deep reds are also found They are cut en cabochon, the star being due inclusions of rutile and may be four or six ray.
NAME, FAME & LEGEND.
The name GARNET comes from the Latin word “Garanatus,” meaning “seedlike,” in referral to a pomegranate. The garnet has been a popular gem throughout history. Garnets were found as beads in a necklace worn by a man in a grave that dates back to 2500 B.C. This is proof of the hardness and durability of the stone.
Garnets were highly popular in Europe, in 18th and 19th centuries. They were used for jewelry in the Victorian times. In Old Spain, the pomegranate was a favorite, and as a result of this, so was the Garnet. In Spanish astrology, the Garnet once represented the sun. In ancient times, garnet was known as”Carbuncle,” which relates to the color and refers to a boil or blister.
The King of Saxony is said to have had a garnet of over 465 carats. Plato had his portrait engraved on a garnet by a Roman engraver. Bohemia, now a part of Czechoslovakia, was once a tremendous source of garnet, and at one time, cutting, polishing, and mounting garnets was a very rich industry in that country. The Anglo-Saxons were also fond of Garnets. Their jewelry was set with Garnets mounted in many forms. Garnet is the birthstone for January and the stone that celebrates the 2nd anniversary of marriage.