Gemstones 101: 03 - Garnets

Educational, Gemstones 101, GemstonesAndrea LiComment
 Image Credit Andrea Li

Image Credit Andrea Li

Garnets have long been heavily associated within a 'semi-precious' stone category. Mostly due to their abundance and average coloration that are typically available. However, with many recent discoveries they now come in an abundance of different colors and can almost cost as much as a sapphire. 

Garnets have a lengthy lineage with personal adornment. Appearing in jewelry for the last 500 years dating back to prehistoric graves found with garnet beads. Even with their long history these enduring stones are far from antiquated. Already the stones favor within the markets is returning. The durability, versatility and variety of colors is making is easy to work with for designers. With the increase of jewelry artists working with the stone consumers are starting to catch on to the stones potential as well. 

The crystal structure of garnets is formed in a cubic system. The system has the highest symmetry of other crystal formations found in different gemstone families. There are eleven different types of garnets. That's one crowded house for a single mineral family. Typical gemstone lineages include on average five to seven different specimens within one particular grouping. Below are some examples of the different kinds of garnets discovered to date. 


Pyrope garnets have a blood red color with few inclusions. The best stones for jewelry design have a fiery scarlet hue that does not darken to much when placed into a setting. 


This is a backlit specimen of Almandite garnets in graphite. They range in color from deep-red to violet-red to even black. Because the stone can be too brittle to cut, the most popular form of use is a cabochon.


Rhodolite garnets have a bright violet-red color with few inclusions. They have a composition between that of pyrope and almandite garnets but are considered superior to both due to their color and lack of flaws. There are only three places in the world this high quality mineral is found. Sri Lanka, Tanzania and Kenya.


Spessartite garnets have a rich orange-red color with feather or lacelike inclusions. These inclusions are unique to them and can be an important identifier to other closely similar garnets. 


This variety of garnet is the purest form of the spessartite garnet. Only found in certain regions in Africa and known for its bright orange color. Gemstone quality of this special garnet is extremely rare and valuable. 


Hydrogrossular garnets have a distinctive gooseberry green color. Translucent to opaque, the common use of this garnet is to be made into cabochons. Often these minerals have a speckled appearance due to the black inclusions of magnetite. Because of their strong resemblance to green jade they are sometimes referred to as Transvaal jade or garnet jade. 


As a result of its brown-orange to brown-yellow color, hessonite garnet is called the cinnamon stone of Africa. Like other types of garnets in this mineral family, their inclusions are distinctive and unique to them. Swirling molasses-like they consist of mostly apatite crystals. This stone dates back to the ancient Greeks and Romans where jewelry from these eras have been found featuring hessonite cameos and cabochons. 


This is the transparent lime-green to emerald variety of grossular garnets. It is nearly always used as a faceted gemstone. The emerald-green color garnets can only produce small stones of two carats and under. This limited size causes them to be more expensive than its lime-green counterparts. First mined in 1968 in Kenya and since had been found in Tanzania. 


Malay grossular garnets are a rather recent discovery. First discovered in Mali not that long ago, giving cause to its name the Mali garnet. The beautiful colors range from golden brown to apricot yellow to peach pink and in some cases green. 


The demantoid garnet is the rarest of all the garnets. There are few stones greater than one carat in weight. Found only in the Ural mountains of Russia. These rare beauties have a higher light dispersion and brilliance of a diamond. This gives them their lively fire and flashing. Demantoid garnets also have yellow-brown 'horsetail' inclusions, a characteristic unique to them.


These garnets are the camelian amongst their other stone family members. They can appear green-blue in daylight and magenta-red in incandescent light. Others change from re-purple to yellow-red. They are a mix of pyrope and spessartite, and also very rare.