From Sally Spencer:
Jewellers, have you ever experienced that heart-stopping moment when you have accidently damaged a gemstone…
As a gemmologist I don't like to see damaged or broken gemstones and as a jeweller I understand how frustrating it can be when that happens, especially when it might be avoided with a little additional knowledge.
Written specifically for jewellers, this guide can live on the bench ready to answer queries when designing or working on a piece of jewellery and includes some gemmological information which could help avoid these moments. 
Covering familiar stones such as amethyst through to the more unusual such as sillimanite, each gemstone has information about its durability and whether it might survive a swipe from a file or abrasive wheel, the pickle pot, repairing or resizing, polishing or cleaning using steam or an ultrasonic cleaner.
Certain visual information can give an indication of how a stone may react during these various processes and details of how to look for some of these using a 10x loupe are explained.
So, before you throw that gem-set piece of jewellery into the barrel polisher or ultrasonic cleaner or light the torch to resize that ruby ring why not double check if there might be a reason not to…