The hugely popular Hessonite and Tsavorite are varieties of Grossular.
In terms of the various families of Garnets, Grossular probably features the widest array of colours. This variety of Garnet gets its name from the botanical name for a gooseberry; “grossularia”. However, in its purist form the gem is white and only becomes different colours such as pink, green and brown when found with different chemical compositions. The tones of Grossular Garnets are often light to medium, making them a very popular gem.
What actually groups members of the Grossular (also known as Grossularite) family together is that in the main they are made up of the minerals calcium and aluminum (Ca3Al2(SiO4). However, sometimes either mineral can be replaced by iron.
Hessonite is a stunning brownish orange Grossular Garnet and unfortunately derived its name from the Greek word meaning “inferior” as it has the least hardness of all Garnets. It is sometimes referred to in the gem trade as the Cinnamon Gem, due to its similarity in colour. In antiquity the Greeks and the Romans set the gem in jewellery, but it was often mistaken for Zircon. Hessonite is said to increase your happiness and to extend your lifespan. Ancient Hindus believed the gem was formed from the fingernails of the demon Vala.
The best known Grossular Garnet is the green Tsavorite Garnet. Tiffany’s in New York gave the gemstone its name after the Tsavo National Park in Kenya where it was discovered by Scottish gemmologist Campbell R Bridges. In “The Curious Lore of Precious Stones” the famous gemmologist George Kunz wrote, “The use of green stones to relieve disease of the eye was evidently suggested by the beneficial influence exerted by this colour upon the sight.
It is interesting to note that although the gem trade tend to refer to the various families of Garnets quite passionately, collectors and gem enthusiasts alike pay little attention to them, preferring to discuss Garnets by their individual names.
Although Tsavorite and Grossular are the most well known members of the Grossular family there are several others including the colourless Leuco Garnet, Rosolite Garnet which is a light pink variety discovered in Mexico and Transvaal Jade Garnet (named after its similar colour to Jade) found in Africa.