Quartz, a silica gem, has a hardness of seven and a vitreous lustre, making it a very suitable gem for most types of jewellery. Different colours and types of chalcedony (cryptocrystalline quartz), from the multi-patterned agate to the beautifully-coloured apple-green chrysoprase, have grown in popularity as the understanding of artistic cutting and carving has advanced.
Variety
Quartz with interesting and arresting inclusions is adding variety and nature’s artistry to bespoke jewellery. Transparent, colourless quartz is referred to as rock crystal and, although common enough in small sizes, it is rare to find large, flawless specimens, which is why the fortune teller’s crystal ball is more often glass and not quartz these days.
Many stunning examples attest to rock crystal’s suitability in carvings, with one well-known example featuring mythological figure Atlas, holding the world aloft.
Rock crystal also features heavily in Art Deco jewellery, and is particularly popular when paired with onyx in black and white combinations. More recently, rock crystal with inclusions has come into vogue, particularly as a collector’s item.
For something really elegant, pale-pink rose quartz (translucent to opaque) looks marvellous when worn against a “little black dress”. Not often found as totally transparent material, large pieces show a pronounced depth of colour and can be quite eye catching when carved.
Brown Quartz
The brown, transparent variety of quartz known as smoky quartz is available in very large pieces, sometimes called smoky topaz, which is incorrect and misleading.
In Scotland, it is referred to as “cairngorm”, no surprise there as it is found in the Cairngorm Mountains in the eastern highlands. Very large stones are cut for plaid brooches and worn as part of national Scottish dress, although it must be said that the stones used these days are probably Brazilian material at best, and paste at worst.
Amethyst
Amethyst, with its colour most royal, has been a great favourite throughout history and is featured in the collection of many royal treasuries. Leonardo Da Vinci wrote that amethyst was able to dissipate evil thoughts and quicken the intelligence, which seemed to work for him!
Amethyst was also traditionally the gemstone of the clergy, and was considered a symbol of piety and celibacy, and many bishops still wear rings of amethyst today.
At the other end of the scale, the Greek word “amethystos” can basically be translated as “not drunken”, and the gem was considered a strong antidote against drunkenness. Amethyst occurs in many shades, from pale lilac to deep purple with the most valued examples being those that carry rosy flashes.
Citrine
Citrine is named after the French word “citron”, meaning lemon. The darker, more orange, shades of citrine are sometimes referred to as “madeira”. Most of these darker citrines started life as amethyst that has since been heated to change its colour – such coloured material is sometimes incorrectly called topaz quartz.
Much of this material comes from Brazil and is readily available in calibrated sizes that looks well when set in gold with other pastel-coloured quartz gems. In ancient times, citrine was carried as a protection against snake venom and evil thoughts.
Purple-to-violet amethyst and yellow-to-orange citrine are staples of the jewellery industry that continue to increase in popularity, yet Ametrine combines the appeal of both of these gemstones in one bi-coloured gem, a must for lovers of amethyst and citrine. Despite the fact that ametrine is sourced from only one location in the world, it is not a particularly expensive gem. Nevertheless, a well-cut ametrine stone with even distribution of colour is typically a thing of much beauty.
Prasiolite
Prasiolite is a green form of quartz that is rare in nature. Almost all natural prasiolite comes from a small Brazilian mine, and it is also found in the Thunder Bay area of Canada. Some green quartz seen in jewellery is heat-treated amethyst, but not all amethyst will turn green when treated. The name Prasolite is derived from Greek meaning “leek”.
No gemstone is more creatively-patterned by nature than agate. It is chalcedony quartz that is formed by filling a cavity in the host rock, and often occurs as a round nodule.
Throughout history, agate has been highly valued as a talisman and at various times and places has been considered a cure for anything and everything. There are many varieties of chalcedonic quartz including bloodstone (heliodor), so named for its blood red spots.
Chrysoprase is a gorgeous green sometimes erroneously called Australian Jade. Orange chalcedony is called carnelian and has been used for jewellery and amulets since antiquity – it is found throughout the world.
Chameleon of gems
To recap, quartz comes in many different forms: rock crystal, with its many and varied inclusions; amethyst, with its regal connections; citrine, in shades of desert sands; ametrine, which provides two colours for the price of one; rose quartz, sometimes enhanced with delicate stars; smoky quartz, for that stone of impact; and prasiolite, for its rarity. If one considers the cryptocrystalline gems, there are agates in all their many hues and patterns, the chalcedonies, chrysoprase and bloodstone, carnelian and sard, onyx and sardonyx.
With such a varied list of options, it’s no wonder that modern consumers are exploring the wonderful world of quartz gems.