Coloured Gemstones

Despite the immense popularity of diamonds, coloured gemstones have always been among the most popular and expressive forms of jewellery. The bright colours of coloured gems give each a unique personality, and personal tastes in colour often dictate preferences for particular stones.

Long before diamonds were found worthy of jewellery, people revered sapphires, rubies, emeralds, and all manner of coloured stones. In addition, almost all coloured gems were believed to have special powers or cure specific illnesses. There was a time when a collection of different gemstones was the equivalent of a medicine cabinet!

Today, gemstones are still loved for their beauty and “personality.” The precious gemstones – sapphire, ruby, and emerald – are among the most prized. Precious gemstones of good size and quality are so rare that a natural, unenhanced, strongly coloured stone can be worth as much per carat, or more, than a diamond of comparable quality.

Given the extreme cost and rarity of such stones, jewellers developed ways to enhance the appearance of more common stones, both precious and semi-precious. For hundreds of years, it has been common practice to heat gems to bring out their best colour. This is viewed as simply extending what nature started, since it is the heat and pressure within the earth that gives gems their colour.

Natural gemstones may have been color and/or clarity treated  by various enhancement processes including, but not limited to: heating (generally); oil/wax/resin (emeralds, opal, tourmaline, turquoise); diffusion (sapphires, rubies, topaz); irradiation (some color diamonds, topaz, tourmaline, morganite); fissurefilled with a glass-like by-product (rubies); or dyed (chalcedony, sugilite). Treatments may not be permanent and/or may require special care. Exposing gemstones to extreme heat, excessive light, chemicals and ultrasonic, steam or abrasive cleaning should be avoided. Generally, gemstones should only be gently cleaned by rinsing in warm water and drying with a soft cloth. Proper care is required in jewelry repair as extreme heat can damage gemstones and/or treatments. Please choose a specific gemstone from the list on the left side of this page for more information about specific gemstone treatments and any special care requirements.

Synthetic or “lab-created” stones, on the other hand, are grown using the same ingredients as the natural stones. They are chemically identical to natural stones, but more affordable, and its easier to get a large, well-coloured lab-created gem than a natural one. Lab-created gems frequently have fewer “inclusions,” the internal flaws common in precious gems. With technical advances, many high quality lab-created stones can only be differentiated from a natural by a trained professional. Almost any gem can be made in a lab, but the precious gems – emeralds, rubies and sapphires – are the most common.

Included in each gemstone description below is its Mohs Hardness Rating, based on the system developed by Austrian mineralogist Friedrich Mohs to compare the relative hardness of different minerals. The scale ranks from softest (talc, with a ranking of 1) to hardest (diamond, which is the only mineral ranked 10). Hardness is the resistance to scratching. When various minerals are scratched against each other, any mineral with a higher hardness ranking will mark any mineral with a lower ranking.

Precious Gemstones
Only three coloured gemstones are considered precious. These are the emerald, sapphire and ruby, which have retained their prized positions among jewels due to their extraordinary colours and extreme rarity. Precious gemstones with good colour and large size are very hard to come by. Because of their rarity, it is common to use stones with inclusions and blemishes in jewellery.

Semi-Precious Gemstones
A semi-precious gemstone includes any gemstone other than sapphire, emerald or ruby. The value of semi-precious gemstones can vary depending on the availability of the mineral; natural black opal, for example, is hard to come by and more valuable than most other semi-precious stones. As a rule, however, semi-precious stones are always more plentiful than precious stones. That makes it easier to find large, well-coloured, very clean stones appropriate for jewellery. In addition, the wide range of colours available makes semi-precious stones the choice for people who want to create their own look with their jewellery.