Often people refer to gemstones as precious and semi precious but there is a more accurate way to describe them which is by their family umbrella. Gemstones are separated into groups determined by their chemical makeup (although there are a few exceptions!) The major groups are corundum, beryl and quartz.

Corundum

Corundum is an aluminium oxide and you will commonly know the gemstones as sapphire and ruby.

Sapphires come in all colours which is due to trace elements being present. For example if iron is present the sapphire will be a yellow/green colour. If chromium is present the sapphire will be pink. The classic blue sapphire is created by the presence of iron and titanium.

The only colour sapphire doesn’t come in is red, as when it is red it is a ruby. A ruby differs from a sapphire as is has chromium within the structure and sapphires don’t.

Corundum is graded 9 on the Mohs scale, second to only diamond, the hardest mineral which is graded 10. This makes sapphires and rubies great for every day jewellery as they are hard enough (within reason) to withstand day to day life.

Beryl

Beryl is a beryllium aluminium silicate and the most commonly know beryl is aquamarine but emerald, morganite, goshenite and heliodor are part of the beryl family too.

Goshenite is the purest form which is colourless. The coloured varieties have trace elements causing the different colours. Emeralds are due to chromium and occasionally vanadium. The most valuable emeralds have a blue hue which is from iron.

The most recognised beryl’s used in jewellery are aquamarine and emerald. They are graded 7.5 on the Mohs scale meaning extra care needs to be taken when wearing them, they are recommended not to be worn every day and will need specialist cleaning with a goldsmith.

Quartz

Quartz is a silicon dioxide and in its purest form is colourless. Trace elements within the structure cause the variations we all know and love like amethyst, citrine, chalcedony (onyx, jasper) and smokey quartz.

Quartz is the most widely known gemstone family and comes in a wide range of varieties. Amethyst and citrine get their colours from different levels of iron and irradiation when forming. Both amethyst and citrine are often found in large deposits around the world, commonly Brazil and Uruguay, and they are used in all kinds of jewellery from high end to costume. With a Mohs grading of 7, beryl gemstones are to be treated with extra care in jewellery and not worn often as they are more fragile.