Cambodia has a wealth of beautiful gemstones. Some, like rubies from Pailin, have established an international reputation for their quality, but other stones are relatively unknown.
Vivid red rubies with good clarity are the most valuable gemstones in Cambodia – the best rubies are rarer than good-quality diamonds. Rubies are recovered from riverbeds around Pailin where prospectors wash through river gravel. It is estimated that 90% of rubies sold around the world are heated to improve the colour. The enhanced colour is permanent. After diamond, ruby is the hardest gemstone and is a good choice for jewellery that is worn every day.
A ruby must be red to be called a ruby: if the same type of stone is pink or orange (or any other colour) it is called a sapphire.
Like rubies, sapphires are recovered from riverbeds, and typically heated to enhance their colour. The change achieved is permanent. Although many people think of sapphires as blue, they come in a wide range of colours, including pink, purple, yellow, and even green. Sapphires have a similar hardness to rubies and are also a good choice for everyday wear. Sapphires are typically more affordable than rubies.
Zircon stones are mined in Ratanakiri, at the opposite end of the country to Pailin.
Not to be confused with cubic zirconia (a factory-made stone), zircons are natural and among the oldest minerals on earth – some in Australia have been dated to more than 4 billion years old.
The stones are typically shades of orange or brown in the raw state, but heating brings about a change of colour to intense sea-blue or even white. Zircons have great brilliance and sparkle.
While they are very beautiful, zircon stones are softer than rubies or sapphires and are a good choice for occasional wear.
Quartz comes in many colours and has many names. Amethysts (from Kampong Thom or Ratanakiri) range from soft lilac to deep purple, while citrine is yellow. Colourless quartz is often called rock crystal. Quartz from Takeo province includes the colourless variety, smoky quartz, and stones that range from pale lemon yellow to an intense golden cinnamon.
While these stones can make spectacular pieces of jewellery, they are best used for occasional wear to avoid the risk of damage.
The best green gemstone found locally is peridot, from Mondulkiri province beside Vietnam. (Emeralds are not found in Cambodia.) Typically a fresh bright green, peridot is both attractive and affordable.
It is softer than rubies or sapphires and about the same as zircon. It is best for occasional wear.
Found in Takeo and some other provinces, topaz in Cambodia is typically colourless, with great sparkle. It is a hard gemstone (less at risk of scratching than quartz or peridot), but can be damaged if it is given a hard knock.
Agate in Cambodia typically has bands of red, brown, yellow and other colours, and has been carved into beads for many centuries. Agate stones can be seen in gold jewellery from the time of the Khmer empire (802–1431).
Cambodia has two types of garnets, one a very dark rich red, the other purplish-red.
Aquamarine crystals in Cambodia are typically a very pale blue in their natural state.
Although not traditionally regarded as a gemstone, obsidian can also be used in jewellery and is popular for its deep black colour. It is a form of volcanic glass that can be faceted like other stones, polished into a smooth cabochon finish, or carved.
Like obsidian, tektites are a form of volcanic glass that can be made into jewellery, but they have been formed in a very different way. Tektites are created when earth rock is transformed and thrown up into the atmosphere after a meteorite impact.
Tektites found in Cambodia were formed from a meteorite strike approximately 700,000 years ago. The meteor crate has not been identified, although it is possible that it is inside Cambodia. Several scientists have suggested that the great lake (Tonle Sap) may be the meteor crater.