Garnet Gemstone Information

Introduction

"The garnet is a red gem, but not like the ruby, its red is much more like that of a flame ... It forms far in the east ... If correctly cut and polished it will reveal all its beauty and perfection."

Aristotle wrote this about garnets over 2000 years ago but our love and admiration for this gemstone continues to this day and we have discovered there are more to this gem than just a flaming red.

Garnets are the 'modern family' in the gemstone world. Not for them a simple chemical formation with one or two impurities to give a bit of color, no this is the gem family with lots of chemical half-brothers, mineral step-sisters, long lost crystal cousins and strange geologic uncles.

This group of closely related minerals has given us a variety of gemstones that appear in almost every color, most often and most famously red but also include some outstanding greens, oranges and pinks and even some purples and, despite what some say, blues.

Garnets are basically the same crystal structure made up of silica and oxygen with an assortment of elements and minerals added to create variations. This variety forms dozens of categories but only a few of these species are important to those of us interested in the gemstone side of the family.

Garnet is broken down into a number of different types or species but we will try to keep this down to just the types that can be turned into the variety of valuable gemstone that we know and love. Other types not used for gems are used as sandpaper, as filters, for waterjet cutting and blasting as well as many other industrial uses.

There are six generally accepted species of garnet (we don't want to get into an argument about what constitutes a species here – we can leave that to the chemists) as follows

• Almandine – the most common form of garnet and is usually dark red to reddish brown in color. It is the hardest type of garnet and when clear enough is cut for use in many styles of jewelry.
• Pyrope – perhaps the most well known garnet, the deep red variety which can rival rubies is the most valued of this type.
• Spessartite – at its best this type of garnet is a clear bright orange color with a special brilliance making it a much sought after gemstone.
• Grossular – in its purest state, this form of garnet is colorless but impurities can turn this gem into a number of beautiful colors including the rare green Tsavorite, one of the most valuable garnets available.
• Andradite – this is the most lustrous of the garnets and comes in many colors most famously green and black but the term Andradite is not often used when describing gems, usually broken down into further groups or types, including the highly prized Demantoid garnets.
• Uvarovite – uniquely for a garnet type, this gemstone only appears in the color green. It is very rare and usually comes in small crystals.

So these are the six main types of garnet and these are the six formally recognized names for the garnet family but these are then divided further into group depending on things such as trade names, colors, sources or are a blend of two or more of the above species. Part of the charm and appeal of the garnet is working out where each garnet fits where in this diverse family.

Rhodolites are a blend of pyrope and almandine and possess a delightful purple hue, Malaya is a mixture of pyrope and spessartite and is pinky orange to reddish orange in color and sometimes called Imperial Garnet. Another pyrope/almandine mix is Color-Change Garnets, discovered in Madagascar and Tanzania, which have the rare ability to change color depending on whether they are in sunlight or artificial light.

An unusual form of garnet worth mentioning here is the Star Garnet, mostly opaque with brownish-red or reddish-black coloring and displaying a 4-rayed star or sometimes even a 6-rayed star. This phenomenon is caused by flaws of rutile needle inclusions correctly aligned to reflect light in a star shaped pattern.

In addition we have the very valuable green garnet, Tsavorite, the dark red or black Melanite, greenish yellow Mali garnet, orange colored Hessonite, the green Demantoids and the pinkish-red Raspberry Garnets. This is but a few of the long list of garnet varieties obtainable.

Some exotic sounding names are used for many sub-types of garnets such as Mandarin, Mint, Gooseberry, Native Sunset, Masai Blue which may or may not be fine gems but the names have been invented in the marketing offices.

Of course some species of garnet are more valuable than others. We shall discus color, clarity, cut and carat in detail in this article but here is a general indication of which variety of garnet is the most expensive.

Tsavorite Garnets, mined in East Africa are a stunning green gemstone only recently discovered and prime examples can fetch up to $5000 per carat or even more. Demantoid Garnets are full of fire and brilliance and gemstones sourced from the Ural Mountains in Russia are possibly the rarest form of garnet. These Russian gems can be 1000s of dollars per carat while Demantoid Garnets found in Namibia are still beautiful but much more affordable.

When one thinks of garnets, the color that usually pops to mind is red, a nice deep red, but garnets come in a wide variety of colors, which is not surprising when you think of the gemstones varied background.

In most gemstones the color variations are caused by impurities within the host crystals. With garnets it is the same story but with such a mixture of chemical ingredients it can be little tricky deciding what mineral causes which color. Some gemstones, including some garnets, do get their color from their basic chemical formula, part of the physical structure of the stone not an added impurity.

We do not want this article to sound like a chemistry lesson so we will keep it as basic as we can. Red and brown garnets are usually red and brown because of the presence of iron during formation, orange and pink from manganese, green from aluminum, chromium or vanadium and yellow from calcium. These mineral impurities can occur in combinations too, so an iron and chromium mix may produce a purple garnet. Much like mixing paints almost any hue is available with a touch of this chemical and a smidge of that one.

At this point it might be worth saying that one chemical, manganese for example, can cause different colors in different gemstones, the orange in garnets, the red in tourmaline and the black in psilomelane.

There are a few candidates for the rarest color in a garnet. The rich orange-red spessartine garnets known as Mandarin are rare and expensive, and there is the trio of rich green garnets, the Tsavorite, the equally green Demantoid and the Uvarovite garnet. But probably the rarest is the Color-Change Garnet from Madagascar and Tanzania which can appear blue in the daylight but change to red or purple under artificial lights. As is usually the case with gemstones, these rare colored garnets are also the most expensive.

Plain blue garnets which do not change color seem to be the only color in which garnets do not crop up.

If you were to have two equally vibrantly colored gemstones of the same size and cut, the clearest stone with the fewest blemishes would be the more valuable. This goes for garnets too. A typical colored garnet gemstone should be eye clean at least and as they are fairly common any blemishes or inclusions are not really acceptable.

When it comes to the rarer and more valuable gemstones the story changes a little. The rule remains the same in that the better the clarity the better the stone but blemishes and flaws within are somewhat acceptable and part of the character of expensive gemstones.

Demantoid garnets are possibly the most valuable of the garnet family but the presence of 'horsetail' inclusions can actually increase its value. These so-called horsetails are fine golden hair-like flaws within the gem and are made of a type of asbestos (totally safe). This unique horsetail inclusion in rare Russian demantoid garnet is regarded by collectors as the most reliable indication of Russian origin, since the more common Namibian demantoid lacks this distinctive inclusion.

Another expensive and rare garnet is the Uvarovite garnet and this stone is generally opaque at best so clarity does not really come into it.

The third of the premium priced green garnets is the Tsavorite and this is more typical of a high quality gemstone. The cleaner the better but it is almost expected that a large natural gem may have some flaws even if it is considered eye-clean.

Chakras are the energy centers in your body also known as Qi or Prana. There are seven Chakras throughout the body each influencing a particular physical, emotional or mental state and each has an associated color. The seven chakras are as follows, Crown linked with the color purple, Third Eye (indigo), Throat (blue), Heart (green), Solar Plexus (yellow), Sacred (orange) and Root (red). Depending on which color is most dominant in your garnet gemstone will determine which chakra it will have most influence on. Garnet has most influence on the root and heart chakras because the gems are predominantly red or green but the solar plexus and sacred chakras will benefit from orange and yellow garnets.

Garnets come in a complete range of prices from a lovely but affordable red pyrope gemstone for a few dollars per carat all the way up to a Tsavorite or Demantoid garnet costing thousands of dollars per carat.

Because garnets come in such an array of colors, rarity and types it is all the more important that you buy your gems from a reputable dealer.

Garnets historically have been mistaken for rubies and while these days scientific methods make this very difficult some merchants may try to suggest that beautiful rich red garnet is a ruby!

The 4Cs, color, clarity, cut and carat size should always be your guide when buying any colored gemstone and garnets are no different but with such a wide range of colors, clarity and even hardness, much care must be taken.

The source of the garnet does not usually affect the price with one or two exceptions – a good quality gemstone is a good quality gemstone no matter where it comes from. However the valuable Demantoid garnets which come from the Ural Mountains of Russia are the most prized and reach much higher prices than those found in Namibia or Zaire in Africa or parts of Europe. Tsavorite is a trade name for the green garnet discovered on the border of Kenya and Tanzania and is pretty much solely sourced from this region although some similar samples have been found in Madagascar.

Garnets are one of the most ancient gemstones known to man, with a history that goes back more than 5000 years and discovered amongst the artifacts of Ancient Egypt and Sumeria.

The Ancient Greeks and Romans traded with the Eastern Empires for red garnets which were probably mined in India and Sri Lanka well before the birth of Christ. In the holy book of the Jewish people, the Talmud, a large red garnet was the only light on Noah's ark.

Chemical analysis has shown these garnets from the Mediterranean world came from South Asia but garnets discovered in northern Europe were mined in what is now present day Czech Republic and Russia.

The modern name garnet was introduced by philosopher Albertus Magnus. In 1270, he described this mineral as granatus, meaning seed or sometimes grain, probably because of the similarity of the single crystals that can be found embedded in rocks to the seeds of the pomegranate fruit.

Russia was the site of a more recent garnet discovery, when Demantoid gemstones were discovered in the Ural Mountains. Their exceptional brilliance and fire let them to be called Demantoid because of the similarity to diamonds. This and their deep green coloring have made them a most sought after and valuable garnet.

A rival to the Demantoid was discovered even more recently. Scottish geologist, Campbell Bridges, who was also instrumental in bringing Tanzanite to the world's attention, discovered a stunning green gemstone to equal the mighty emerald in the Mereleni Hills of Tanzania. At the time it was illegal to export gemstones from Tanzania so Bridges crossed the border and found the other end of the rich mineral vein in Tsavo National Park in Kenya. His employers at Tiffany's came up with the name Tsavorite in honor of its place of discovery. Campbell Bridges was brutally murdered some years later in what may have been a confrontation over mining rights.

With so many different varieties and so many different chemical formulas, garnet can be formed in many ways but in general, garnet crystals form when sedimentary rock is subjected to immense pressure and intense heat, often in the case where two continental plates converge together. The heat and pressure essentially melt the rock and it as it cools it crystallizes in cracks and gaps in the metamorphic rock surroundings. The garnet is a silicate material and when mixed with other chemical impurities create crystals in a variety of colors.

Garnet is a very hard material and over the course of millions of years the surrounding rock can wear away and the remaining garnets can be washed down into streams where alluvial miners await. Garnets formed in much stronger rock or are younger geologically can be reached through shafts cut into mountains to reach the veins of crystals.

The mineral Garnet is found all over the world and is quite common in its base form and is used industrially as an abrasive material for sandpaper or as a filter. However as a gemstone it is less easily mined.

The different species and types of garnet are mined and different locations around the world, precious Demantoid in Russia and Namibia, Tsavorite in Kenya and Tanzania, pinkish red rhodolite in India and Sri Lanka, Mandarin garnets in Namibia but the top producers of garnet as a whole are Australia, the US, India and China.

Apart from the standard cutting and polishing, garnets are not treated in any way.

Rather rarely in the world of gemstones, garnets are not affected at all by heat or by irradiation so are never heated.

There are reports and rumors that Demantoid gemstones from Russia are heat treated to improve color and clarity. The treatment is at low temperatures and is undetectable in the laboratory so you will have to trust the dealer where you buy your gems to disclose any known procedures.

Garnets have a relatively wide range on Mohs hardness scale, Demantoid garnets are 6.5 to 7 on the scale and Pyrope and Tsavorite are 7 to 7.5. All garnets fall between 6.5 and 7.5 so are strong enough to be used in almost any style of jewelry although we would suggest removing the jewelry while participating in any vigorous activity such as sports, gardening or house cleaning.
Find all details about the Mohs scale in our article here

To be extra careful, especially with more expensive varieties it would be wise to have jewelry with more protective settings such as a bezel for a ring or wear the garnets as pendants or earrings where they are less likely to get knocked or hit.

While they are strong enough to withstand the rigors of daily wear care should be taken to avoid any sharp blows. Crystals should be stored carefully to avoid contact with hard materials which could break, chip or scratch the gem or any softer gems which could be scratched by the garnet.

Garnet comes in a stunning range of colors and mostly at very affordable prices but are not often found in very big carat sizes so bear that in mind when thinking of a design for your gemstone jewelry. Regular garnets are cut into standard shapes and standard sizes for ease when setting into jewelry but the expensive Tsavorite and Demantoid are usually cut in a way to best show off the gemstones finest qualities.

If you are setting a garnet gem in a metal, the choice of metal will come down to a matter of taste and the choice of colors mean that you will be able to find something to match any metal alloy.

Birth months and zodiac signs have been linked with gemstones for centuries, possibly going all the way back to the breast plate of Aaron, the brother of Moses, mentioned in the bible. These gems have changed over the years, been renamed, been mistaken for other gems and varied from culture to culture. Red garnet was probably one of the original stones of this breastplate although we cannot be certain because of disputes over translation and determining what stone was what in those days.

What is not in dispute is that garnet is now the official birthstone for January. About 100 years ago the gem industry in the United States decided to set out the 'official' birthstones for each month (very much a money spinner more than a cultural event). Any one of the huge range of garnets would make an ideal gift for a loved one born in this month.

• Let nature do the work

  Miners in Arizona get help in the most unusual way. Ants digging new homes often find little garnet gemstones blocking their passageways so they haul them to the surface and push them away. The rain washes them off the hillsides into little gullies where locals can collect these little ready-tumbled gems. They are called Anthill Garnets!

• Garnet is the perfect gift for the 2nd anniversary what better way to celebrate the early years of your relationship than with this lovely gemstone.
• Ancient Roman nobles and politicians used carved garnet signet rings as stamps to seal the wax on important documents
• Keeping Mum

  Thousands of years ago, red garnet necklaces were worn on the necks of the Pharaohs of Egypt, and were buried with their mummified corpses as cherished possessions for the afterlife.

• Whose side are you on?

  Garnet served as a talisman in the Crusades in the 11th and 12th centuries for both the Christians and their Muslim enemies. It was called the Warrior Stone and was carried in many battles.

• Biggest Garnet ever was dug up in New York City!

  In 1885 workmen working in the sewers beneath New York City discovered a 10 pound (4.5 kg) garnet that was the size of a bowling ball! It was named after George F Kunz and, after serving time as a doorstop, The Kunz Garnet now resides in the American Museum of Natural History.

• The largest Tsavorite ever found

  A deep green Tsavorite gemstone was discovered in East Africa and is a little smaller than the Kunz Garnet, however at 325 carats and crystal clear it is valued at over $2 million.

• Gemstone Viagra!

  Physically, the garnet could help men in the bedroom if placed on the appropriate part of the body. Princess Palatine, who is featured in the new TV series Versailles, found her husband, positioning garnets on his body in this way. Although he begged her not to tell anyone, to his embarrassment, she told the whole court and wrote about it in her many famous letters.

Warm, soapy water and a soft brush are the safest way to clean all gemstones, and garnet is no exception. Ultrasonic cleaners may be used with garnet, though they are generally not recommended by professionals because the vibrations can loosen jewelry settings and cause your garnets to become lost.

After cleaning your garnet with a mild detergent, rinse it with clean water and dry it with a soft cloth. Air drying a gemstone will leave unsightly spots and disrupt the garnet's sparkle.

Garnet species are very durable, but they can incur damage if not stored properly. Each piece of garnet should be kept separate from other gemstones and pieces of jewelry in a dedicated compartment of a fabric-lined jewelry box, placed in a cool and dry location. Individual cloth jewelry bags are also suitable if you have limited space in your box.

Another space-saving method is to use acid-free paper envelopes, called "parcel paper envelopes" or "diamond papers", to keep gemstones of the same hardness together and arranged in a parcel paper organizer box. Glass jars with foam or fabric inserts are perfect for those who want to showcase their loose gemstones and jewelry.

Obviously a certified gemstone from a reputable dealer is the best approach but this is not always possible when you are out searching for a great gemstone or a bargain! Garnets cover the entire range of prices from very affordable to very expensive. With the simple red pyrope garnets it is best to find a good supplier that you trust and buy them without the expense of any certification. However the more expensive the garnet the more careful you need to be.

A couple of simple checks will be able to determine a real garnet from glass or an inferior gemstone. Put the garnet close to your eye and look at a source of light about 2 meters away. Within the stone you should be able to make out a rainbow which includes yellows and greens. No rainbow or no greens and yellows means it is probably not a garnet. Scratch test. Garnets are around 7 on the Mohs hardness scale so a steel blade or an iron nail should not be able to scratch the surface, if they can it is not a garnet.

If you are thinking of buying a valuable Tsavorite or Demantoid garnet stone, we could not emphasize more the importance of a trusted seller with a good return policy. The stone should come with a certification or you should be able to have the stone you purchased certified with the option of return if it is not what it claims to be.

Price as a guide. Some garnets such as Tsavorite, Demantoid and Mandarin are rare precious gemstones so the price should reflect this. If you see a prime example at a price too good to be true, it probably isn't true, so avoid buying such 'bargains'.

This is not a complete guide on how to spot a fake gemstone but I hope it helps.

At GemSelect, we currently offer brief identification reports from your choice of two well-respected independent gemological laboratories, The Asian Institute of Gemological Sciences (AIGS) and Burapha Gemological Laboratory (BGL Lab).

Some gemstones show a distinct or dramatic change in color under different light sources. Look at some garnets under electric or artificial light and it could look red, take one outside into the sunlight and all of a sudden it is green! This remarkable effect only occurs in a few gemstones, and certain garnets are one of them!

Color-change garnets are a remarkable phenomenon. Many garnets have this ability but it is usually subtle and difficult to see except in the astonishing gemstones from Bekily in Madagascar which can change dramatically from blue to pink when moved from light source to light source. Other garnets have the ability to change color too but none can match the striking changes of the Madagascan gemstones.