For many of us, even though we love the red colour of a ruby, it is often too expensive for our budgets. Fortunately, there are some gemstones that can simulate this precious stone, one of the most affordable of which is Garnet.
This January birthstone is an abundant species that surprisingly comes in many colours of the rainbow. Although it is associated with hues of red, garnets can actually range in colour, spanning blue, green, yellow, orange, red, pink, brown, black – even colourless. What produces colours in garnet are trace chemical elements (iron, chromium, vanadium, titanium and manganese) or defects in the crystal structure. Garnets with a pure form, such as grossular and pyrope that do not contain metals in their formulae are colourless.
Some of the garnet’s properties include ferromagnetism, where it reacts to magnets due to the iron in its composition (particularly true of almandine, almandine-pyrope, spessartine and andradite), and its ability to generate electricity when is rubbed or heated.
With a hardness of 6.5-7.5 on the Mohs scale garnet has a few varieties that are suitable for jewellery including:
Pyrope & Almandine
With prices that can vary between $1-$100 per carat, pyrope garnet and almandine garnet are the most common varieties of this gemstone. Bear in mind that these prices are affected by hue, saturation of colour, clarity and dimensions. A gemstone of 1 carat is much less valuable per carat than one of 5 carats. Blood red (due to iron and chromium impurities), dark red and pinkish red are associated with both pyrope and almandine varieties. Pyrope has a Mohs hardness of 7¼ and is usually faceted as brilliant and mixed cuts, and almandine has a Mohs hardness of 7½ and is usually faceted as mixed and cabochon cuts.
[left]Almandine garnet is the oldest garnet. Although dense, almandine is brittle, and facet edges chip easily (take particular care if you wear a ring that has this gemstone). “Almandine” is named after a small town in Turkey, Alabanda, a source of this type of garnet and a cutting centre which the Roman naturalist and writer Pliny the Elder mentioned in his works. Other places where is it mined in great quantities are India, Australia and Sri Lanka, to name a few.[/left]
[left]Pyrope garnet is a magnesium aluminium silicate that started being mined in the Bohemian fields (Czech Republic) in the 16th century. At that point, it wasn’t so highly valued because the market was saturated with cheaply made Bohemian jewellery. The word “pyrope” comes from the Greek “pyropos” meaning “fire”. When pyrope garnet is cut and faceted, there is a change of colour, with the darker tone converting into a lighter red. Faceted stones rely on internally reflected light, which produces a more intense hue. The mid-tonal ranges of colours are the most popular. The localities where it can be found are in the USA (Arizona), South Africa, Australia, Brazil, Myanmar, Scotland, Argentina, Switzerland and Tanzania. For every 2 tonnes of garnet mined only one gemstone will be over five carats.[/left]
[left]In contrast to almandine, spessartine garnet is the most recent type of garnet to be discovered. With a Mohs hardness of 7, the ideal stone is bright orange due to iron impurities, but an increase of these impurities in the chemical composition causes the gem to become a darker orange to red. It is rare to find gem-quality stones, and they are usually faceted as brilliant, step and cabochon cut. Spessartine is named after the Spessart district of Bavaria, Germany, and there is no history of this gemstone before the 19th century.[/left]
Grossular garnet is the most varicoloured of all the garnets. In its pure state, grossular is colourless, and it is various impurities that cause the vast varieties of colours that can be found. The name derives from the botanical name of the gooseberry, R. grossularia, in reference to the ones found in Siberia, which were green. The most beautiful and attractive grossular garnets are the orange-brown- hessonite and the stunning green- tsavorite.
Hessonite garnets are coloured by manganese and iron impurities, have a Mohs hardness of 7¼, and are usually faceted as brilliant and mixed cuts. In contrast, green grossular garnet/tsavorite has a Mohs hardness of 7, and is usually faceted as brilliant cuts and beads. [left]
Tsavorite is also one of most expensive varieties of garnet due to its rarity and incredibly beautiful green colour, which is very similar to that of Emerald. It was first discovered in Tanzania in 1967, and deposits were also found in Kenya soon after, in 1970. In fact, Tsavorite is named after Tsavo National Park, in Kenya.[/left]
Demantoid (Andradite Garnet group)
[left]Demantoid garnet (Calcium aluminium silicate) is a beautiful yellowish-green gemstone of a Mohs hardness of 6½, which, after cutting and polishing, will have a similar brilliance to that of a diamond. It was first mined in the Ural Mountains in Russia, and the legendary Russian jeweller Carl Faberge was famously hugely passionate about this gemstone and used it often in his masterpieces. Nowadays, this beautiful green garnet can also be found in Namibia, and it is thanks to these deposits that it is not as scarce as it once was, although the gemstones found are small in size. The open-pit Dragon Mine from Namibia has an annual production of between 5000-10000 carats. Demantoid is usually faceted as brilliant and mixed cuts.[/left]
Historical facts about garnet
Garnet was rarely used by ancient cultures. The oldest object that exists is in the Louvre Museum in Paris. It is a cylindrical seal, made of grossular garnet, which belonged to the royal scribe of the Sumerian King (21st century BC) of the city of UR in Mesopotamia (now southern Iraq).
It was with the conquest of the Persian Empire by Alexander the Great that garnet began to be more widely used. The geographical change facilitated an exchange of cultures between the Greek, Asian and African worlds, and was the starting point of an international trade of emeralds, sapphires, rubies, topaz, diamonds and garnets.
In his book on “Natural History” Pliny the Elder noted that is hard to differentiate between the different types of garnet, and that the colour and the shine was said to improve by soaking the stone in vinegar for 14 days.
After the fall of the Roman Empire, during the so-called “Dark Ages” this gemstone became very popular and a new trend called “garnet cloisonné” (numerous small cells containing polished garnet, glass and enamel inlays that were separated by thin strips of metal) emerged. Extraordinary garnet-rich cloisonné has been found in 4th-century graves in Simleu Silvaniei and Pietrosa Romania.
At one point during the 17th century, the price of garnets could equal that of rubies, although after approximately 50 years they dropped in value. In the 18th century garnet intaglios came into vogue, and The State Hermitage Museum in St Petersburg exhibits some pieces that belonged to Catherine the Great.
[left]The demand for garnets began to rise again during the late 19th century as it became more popular in Victorian jewellery.[/left]
*Other interesting historical snippets abound
A bestiary called “The Hortus Sanitatis” relates an unusual test for authenticating garnet in which a person, lubricated with honey, had to lie naked next to a wasps’ nest wearing the garnet that was to be tested. If wasps or flies approached the person, then the gemstone was deemed to be a fake. In “The Curious Lore of Precious Stones”, George Kunz indicated that some tribes in Asia were using garnets as bullets (these blood-coloured stones would inflict a more deadly wound to their enemies), and that, somewhat contrastingly, garnet was believed to stop headaches if it was put on the head.
As you can see, garnet is a vast family with many options suitable for jewellery. Hardness is often a decisive factor when we want to make or buy a piece of jewellery, and most of the garnet varieties are fairly hard. It is always worth remembering, though, that a ring, which is more exposed to knocks or accidents, should always have gemstones that are harder, whereas earrings and necklaces are less likely to be damaged, and therefore are more subject to taste and optical properties (colour and lustre) than to physical ones.
*all images are from pinterest.com