You probably know garnets as reddish-brown gemstones sometimes used as a substitute for ruby. Whilst they do come in this colour, there is a lot more to this family of minerals than that!

Some of the most interesting gemstones finds in the last 100 or so years have included varieties of garnet, found in locations as varied as the Ural mountains in Russia to the Tsavo National Park in Kenya.

Garnets come in a wide range of colours and each colour has a different name. When it comes to jewellery, there four main types of garnet that you need to know about. If you’re a gemologist then you’ll know that some other categories and classifications have more to do with the exact chemical composition of garnet crystals. The trade names, which are used for jewellery, are often chosen because of the locality in which they were found, like tsavorite, found in Tsavo National Park, or because they resemble another gemstone, like demantoid, which resembles diamond.

As well as red, garnets also come in orange, green, yellow, and blue. Blue garnets are one of the rarest gemstones on the planet and these stones can also change colour in a similar way to alexandrite. Although garnets have been known about and used for millennia, blue garnets were only discovered in the 1990s. Garnets measure between 6.7 -7.5 on the Mohs scale of mineral hardness and this makes them suitable for most types of jewellery and they are a popular choice for jewellery designers.

Types of garnet

Demantoid - Olive green, yellow, and brown

Demantoid Garnet from Namibia, image courtesy of Edward Fleming Jewellery

Tsavorite - Light mint to dark emerald green

Spessartite - Orange

Spessartite Garnet from Namibia, Image courtesy of Edward Fleming Jewellery

Rhodolite - Red/pink

Rhodolite garnet from Tanzania, image courtesy of Edward Fleming Jewellery

Pyrope garnet - red, black-red, purple-red, orange-red, and colourless

Where do garnets come from?

Garnets are found on every continent, however, some varieties are found in only three or four places on earth.

Demantoid Garnet - Russia, Namibia, Italy, and Iran

Tsavorite Garnet - Kenya, Tanzania, and Madagascar

Spessartite - Namibia, Australia, India, Afghanistan, Nigeria, Myanmar, Mozambique, and Tanzania

Rhodolite - North America, Tanzania, Kenya, India, Brazil, and Greenland

Pyrope Garnet - South Africa, Australia, India, Brazil, North America, Russia, China, UK, Germany, Austria, and Czech Republic.

Ethically sourced garnets

To work out whether a gemstone has been ethically sourced or not, you need to know as much about that gemstone’s journey from mine to you as possible. With garnets, this can be relatively simple or very hard and it can differ greatly from type to type.

Tsavorite - Tsavorites are an example of garnets that are found in only a few places on earth and they can be relatively easy to trace. For instance, the original commercial claim in Kenya is still owned and operated by the Bridges family, who are well regarded within their local community for treating workers well, contributing to the local economy, and are transparent about where their stones are cut and processed.

Arusha, in the north of Tanzania, is the centre for the worldwide tsavorite trade and buyers from Sri Lanka and other southern Asian countries, which supply the domestic Chinese market regularly visit to buy rough gemstones. There are many mines in the area surrounding Arusha and there is a smaller gemstone trade in Merelani, to the north of Arusha, where miners from the surrounding area sell their stones to dealers who then sell to dealers in Arusha. This means that even by the time the rough gemstones have left Tanzania they have been through several hands, which makes tracing them to the mine difficult.

Demantoid - Due to the secretive nature of mining in Russia, it’s very hard to know the exact conditions at the mines in the Ural mountains. Small scale mining in Namibia continues and though mining in this country is tough, especially in the dry conditions pay and conditions are reasonable in comparison to other countries in Africa and government initiatives to help small scale miners

Garnet Jewellery

As garnets measure from 6.5-7.5 (depending on the type) on the Mohs scale of mineral hardness, they are suitable for most types of jewellery, including rings, except for engagement rings.

Some varieties of garnets, like demantoids or tsavorites, can fetch very high prices at auction when mounted in jewellery. Demantoid garnets have a special association with legendary Russian jeweller Carl Fabergé and pieces by him with Russian demantoids are particularly sought after.

Garnet Mining

Garnets can be mined using both open and closed pit mining as well as alluvial mining. Most garnet mines are small scale as gemstone quality garnets often exist in small ‘pockets’ that do not require large quantities of earth to be removed. However, tunnels may need to be long and deep to follow the seams of rock in which these pockets can be found.

At first, these mines can be very small, possibly just a few metres deep and these types of mine have a minimal environmental impact and pose few hazards to miners, however, both of these factors increase as mines become deeper.

Depending on where in the world the garnet deposit is located, mining could be done by hand, using only basic tools or somewhat mechanised with excavating, ventilation, and sorting equipment.

Garnets Mined by Ants

In North America, the phenomenon of garnets being brought to the surface by ants digging nests is so frequently observed that it is possible to buy jewellery containing garnets that have been literally mined by ants.

Ants are famously able to carry several times their body weight and they can remove stones of up to 1.5ct in weight. As the ants come across these stones whilst digging their tunnels, they bring them to the surface and discard them at the top of their anthills. Over time as, these stones are washed, blown, or pushed from the top and collect at the bottom of the anthill.

Garnet Meaning

As garnets are a relativity common mineral, they have been known to many different cultures throughout history, which have attached various sets of beliefs and meaning to the stone. In Persian culture, garnets were associated with nature’s forces, such as storms and lightning and they were used as a talisman.

Engraved garnet rings were used to stamp seals in both Greek and Roman culture and in tombs discovered in Egypt, examples of garnet jewellery and talismans have been found. The Romans especially used Garnets prolifically to adorn all kinds of objects.

In tropical astronomy, Garnet is associated with Aquarius.