Topaz, the birthstone for November

Colours
Like the natural shades of November, Topaz comes in many warm and beautiful colours. Brown, red, orange and sherry yellow are the most Autumnal of Topaz’s hues, however they can also be found in other colours such as blue and pale pink. The most valuable colour of topaz is called ‘Precious’ Topaz, which is orange in colour with pink undertones. Blue topaz is the most common form found in jewellery today however it is the most rare colour found naturally. The most common form of Topaz found is colourless, so many of the coloured Topaz you see today, especially the blue, have been heat treated in order to enhance its colour. The vibrant pinks recently marketed are diffusion surface treated, which is to a great extent a non-permanent treatment.

Physical Properties
Topaz is a hard gemstone rating eight on the Mohs scale of hardness (10 being the hardest). However care must be taken with it as a single blow across the cleave line can split it in two (a trait shared with Diamonds).