Garnet is a type of mineral silicate that is usually found in metamorphic rocks, magma columns and other formations connected with lava and volcanic eruptions. It is scientifically recognized as a “rock-forming mineral” and shares attributes with many other minerals.
There is an entire family called the garnet family with multiple species and subtypes involved. Garnet’s chemical structure can have different impurities or inclusions, including iron, manganese, vanadium, and the like. Each type of pollutant or composition can change the color of the garnet.
This mineral family comes in a dazzling rainbow of colors, which is fantastic for collectors who want to have as many gem species as possible from each tree or family of gemstones. The most easily recognized type of garnet is the red one, and we are going to discuss the most common garnets used in jewelry, so you are familiar with these popular gem species.
Types of Garnet
The garnet family is known either for its intrinsic beauty (as gemstones for jewelry) or its renowned toughness since it registers a hefty 6.5 on the Mohs scale of hardness (and this is just the minimum).
Garnet has long been in use as a raw material for high end polishing and scouring products like sandpapers and other abrasive surfaces. In particular, Idaho has many manufacturers that use garnet precisely to manufacture sandblasting materials, garnet abrasives, water-jet cutting technology, and more.
The garnet that we will be talking about today will be the garnet species renowned for their beauty, especially their garnet color. Garnet is the birthstone for folks who are born in January and is one of the most bright gemstones in the gem world. Its clarity and visual characteristics are unmatched, and it has a refractive index that easily exceeds the refractive index of a diamond, the hardest mineral on earth.
A quick examination with a dicroscope can help reveal if a mineral specimen is indeed a garnet or something else. Expert jewelers will be enabled to compare the refractive index and compare it to the averages for each type of mineral or gemstone family. Garnet is also one of the rare minerals that have no counterparts because they already look amazing on their own minus the heat treatments, pressurizing, and irradiation.
Six types of garnet are considered the best for jewelry settings and other ornamental applications.
- Uvarovite – This is the only garnet type that occurs in just one color. The green uvarovite is also considered the rarest kind of garnet because it never appears in large blocks or chunks – only tiny fragments of crystals.
- Andradite – Andradite has the highest index for luster among all the members of the garnet family. It is highly sought after, and like uvarovite, it also comes in a deep green color perfect for jewelry.
- Grossular – Grossular is known for having the most transparent crystal structure among all the garnets. Its subtype, the Tsavorite, is one of the priciest garnets in existence. Tsavorite is a high tier type of garnet because of its beauty and clarity.
- Spessartite – The orange garnet, spessartite, is known for being the brightest species of garnet.
- Pyrope – Pyrope is the most popular and well-known of all the garnets because of its deep red color, which is so apparent to the naked eye that people often mistake pyrope for rubies.
- Almandine – In contracts to pyrope, almandine garnet is of a darker red hue and sometimes even appears as a brown mineral.
Some garnets appear black even though, in reality, they are reds so deep that they appear black to the naked eye. You can identify the color of these deep red ones by shining a powerful light through the mineral.
Which garnet is the most valuable?
Garnets cannot be easily categorized as either semi-precious or precious stones. Some garnets can be purchased as cheaply as $10 or less, while other sub-types fetch $1,000 per carat easily. The value of garnet increases exponentially. So, for example, if you happen to have a five-carat specimen of green Tsavorite, that can easily fetch $50,000 or more depending on where you are going to sell it.
The rarest and most valuable garnet forms are the ones in green, peach, and the obvious ones, too. Red garnets (pyrope or almandine) are abundant in nature and will not fetch as much, especially if they are unprocessed.
And let’s not forget that there is also a high demand for color-changing garnets. Color-changing garnets bend light in a tricky manner, much like alexandrite. Color-changing garnet will have a different reaction to natural light and a separate light show if you expose the mineral to incandescent light.
Where Are Garnets Found?
Garnets are found throughout the world. Spessartite garnets are usually mined from Madagascar. These garnets can be orange, red, and sometimes even yellow. The rarest are the yellow spessartite garnets. If miners do find some yellows, they’re usually from another subtype, which is grossular garnets.
If you want green garnets, you’d have to get your supply from as far as Kenya and Tanzania, too. Madagascar is a relatively new player in the game, but it is somewhat leading with the production of fashionable green garnets, which are highly prized anywhere in the world.
How Much Are Garnets Worth?
The value of garnet largely depends on the size of the stone and other factors, such as clarity, color, and cut. Like we discussed earlier, you can buy some garnet setting below $100, but in some other cases, the price is going to increase depending on the quality of the stone itself.
A garnet ring, for example, more than one carat, can easily fetch $5,000. The rarest, if you want to set a challenge for yourself, is to find a genuinely colorless species of garnet. Many jewelers will swear up and down that they have never truly set their eyes upon a 100% colorless specimen of garnet. Colorless garnets are truly rare and are even scarcer than rubies and sapphires.