The “classic” coloured gems remain ruby, sapphire and emerald. However, the modern range of coloured gemstones is much more extensive than that. As the demand for coloured gemstones increases with increasing population and improving living standards, new sources of gemstones and indeed new varieties of stones are being found and produced. For example, rubies have been found in new locations such as Burma and Vietnam as recently as the 1990s. In understanding the full range of coloured gemstones it should be appreciated that they should be divided into a number of groups:
Coloured and Transparent
This group is usually seen in the form of faceted stones (ruby, sapphire, tourmaline, topaz etc.) where skilful cutting can achieve a combination of colour and brightness from the stone. These materials are increasingly being seen in the form of high quality cabochons while included material is used as beads.
Coloured Translucent to Opaque
These materials provide much of the material cut as cabochons, beads and carvings. Their main features are their colour or colour patterns. Examples are Lapis lazuli, jade, turquoise, malachite, agate etc.
These are materials with special visual features or effects such as star sapphire, cats eye chrysoberyl, precious opal etc. These materials are cut as cabochons as this style of cutting tends to enhance the optical effects of the material.