Gemmology is such a huge and fascinating subject. It took me 3 years to qualify as an FGA (Fellow of the Gemmological Association) passing in 1993. My young son loved testing me from my flash cards when we were on long car trips! This qualification is the highest to achieve in Great Britain, requiring an 80% pass rate for written and practical exams and only concentrates on Gemstones. There is a different Diploma to take for Diamonds, although the FGA teaches the basics.

My knowledge is based on the science of gemstones. I have to consult The Crystal Bible to answer queries about their energy and healing qualities. 

To pass the exams, we had to learn and memorise information for approximately 100 gemstones and all their groups. Did you know for example, there are 6 different colours and names of Garnet? The familiar Red, also Golden, Pink/Red, Red/Purple, Yellow/Orange and Green. Green Demantoid Garnet is highly prized because it’s so rare and mainly comes from the Ural Mountains in Russia. It’s a very bright stone with inclusions of golden curved fibres called ‘horsetails’ and can often be found in Victorian jewellery.


I was astonished to learn that Ruby and Sapphire are actually from the same family called Corundum! Rubies are coloured by Chromium Oxide and Sapphires are coloured by Aluminium Oxide and Iron during the formation of the crystals. So a Pink Sapphire is not a Ruby! Also the Black Prince’s Ruby in the Imperial State Crown was found, when tested, to be a very large Red Spinel.

Another interesting fact is that Tourmalines have the largest variety of colours. The colour starts from the top of the crystal to the bottom, from dark green, through to blues, pinks and yellow with many colours mixing, causing bi-colour stones depending how they are cut.

The jeweller’s friend is a 10x magnification loupe which we will use to look for natural imperfections or inclusions for identification, however there are lots of other tests. If there is a nice flat surface, stones can be tested using a refractometer. This measures the angle that the light bends passing through (refraction), the same effect that causes a stick in water to look bent. Every gemstone or variety will have its own reading, I can’t remember them all now though, thank goodness for books!

If you would like to read my Blog on my website, I often choose a stone to talk about for your interest.