From the ancient Egyptian Pharaohs who used them for ceremonial and decorative purposes to the discovery of large deposits of red pyrope-type “Bohemian” garnet in Czechoslovakia in the sixteenth century, garnet can be traced back throughout the ages. The popularity of garnet reached dizzying heights in the nineteenth century when used for Victorian jewellery yet it is still celebrated today.
Garnets are a truly international family with homes in China, Madagascar, Russia, Africa, Brazil, Sri Lanka and Australia. Although the name garnet is derived from the ancient Latin word ”granatum”, meaning dark red, many other colours are available including orange, yellow, green, purple, brown, black and pink.
The gene pool
The garnet gene pool comprises two main families. Each family has similarly-sized chemical elements that may be substituted for each other to produce different colours, inclusions and properties by which garnet is identified. No garnet is completely pure and usually contains two or more varieties.
The most famous garnets are the pyralspites, aluminium rich silicates consisting of pyrope, almandine and spessartine. The other lesser-known group are the ugrandites, calcium rich silicates comprised of uvarovite, grossular (tsavorite, hessonite) and andradite (demantoid, topazolite, melanite).
Popular is the iron-rich almandine variety. It is usually dark red but may also display violet, brown or orangey tones. Commonly sold in calibrated sizes, almandine is among the least expensive of all garnets due to its widespread population.
Almandine garnet’s hot blooded and hard-to-find relative pyrope is coloured by chromium and iron and is pure bright red, violetish-red or brownish red.
Rhodolite garnet ranges from deep rose or pinkish-red to purplish-red and is far more valuable than almandine.
The flaming red of spessartine is due to manganese. Prized for its Fanta-orange colour, this little-known gem is rare and priced per carat. Spessartine often has eye-visible inclusions, a trait shared with another orange garnet called hessonite.
The green garnet tsavorite is coloured by vanadium or chromium. Demantoid is the most expensive green garnet of all and is coloured by chromium and iron. It has a very high dispersion and adamantine lustre and its German name means “diamond-like”.
The gatecrasher of the party is malaya garnet, an exotic orange to reddish-orange pyralspite species with pinkish overtones whose name is fittingly derived from the Swahili word meaning “no family.”
Other exotic relatives include a green to brown garnet named mali, a homogenous compact pink or green rock called massive hydrogrossular garnet and a black andradite garnet called melanite. Don’t forget those fabulous colour change garnets that change from blue to purplish-red or from green to purplish-pink.
The entire garnet family has a natural beauty envied by many. Consequently, it is rarely enhanced. Pyralspite is suitable to be worn every day but all varieties are vulnerable to hard knocks and rough wear. Clean them in warm soapy water or use an ultrasonic cleaner unless they have fractures.