A Guide to Gemstones

The beauty of stones


A type of quartz, the regal, purple colour of amethyst varies from location to location. Pale stones used to be foiled to enhance the colour, and deep colours are considered the most valuable. The colour is due to the presence of iron.

Amethyst also occurs with other crystals – when it is juxtaposed with a colourless crystal it is called ‘amethyst quartz’ and when it is banded with citrine, it is known as ‘ametrine.’
The word derives from the Greek word amethustos, which means sober, and it has the reputation of protecting the wearer from becoming drunk.

Beads can be tumbled, which gives them a lovely tactile quality, or cut to enhance the colour. Brilliant, baguette and mixed cuts are all popular.

Sources range from the amethyst of Jalgaon, Maharashtra in western India, which is considered to produce some of the best examples. Southern Brazil, Sri Lanka and Uruguay also produce lovely amethyst.


This is another variety of quartz, rarer than amethyst – which can be heat-treated to produce the yellow colour of natural citrine. In fact, most citrine today is artificially created from amethyst and it is difficult to tell the difference between the two, although heat treatment is said to produce a faint red tint. It takes its name from the French word for lemon, ‘citrin’.

Valued for its rarity, citrine was used by the Romans and Victorians especially. The darker the stone, the more valuable – the colour is due to the presence of ferrous oxide.

Citrine can be mistaken for topaz, which is much more expensive. Beware – stones called ‘topaz quartz’ or ‘citrine topaz’ are citrine that is being deliberately confused with the more valuable topaz!

More to be added soon