The sapphire, ruby and the pathmaraga of the corundum family have specific identifying names of their own whereas the other varieties (other than asteriated types) are all referred to as sapphires but with their respective colours prefixed, as has been mentioned earlier in this chapter. Among yellow sapphires various shades are noted varying from pale yellow to saffron yellow and from yellow slightly tinted red to a deep citron yellow. Iron is basically the colouring element that is responsible for the colour. In local terminology the yellow sapphires are identified as 'pusparaga' Yellow sapphires are widespread and are found in all corundum producing areas, one of the most reputed areas being places around Aluthnuwara in the Balangoda region. Among allied colours are varieties identified as golden sapphire and orange sapphire. While the colouring elements are the same as in yellow sapphire, the golden sapphire is found to contain traces of chromic oxide as well, as revealed by the hand spectroscope (doublet at 6924 AO and 6928 AO). These colours are very much in demand and these are locally identified as 'ratnapusparaga.' These gemstones when perfectly transparent are extremely attractive.
The orange sapphire is yet another variety with a deep orange colour, the demand for which is now on the increase. These beautiful deep orange colours could also be produced by subjecting certain types of 'geuda' corundum to intense heat and these treated corundum are rather common.
The other colours in which corundum occur are green and its various shades (yellow green, bluish green) and purple, brown, pink and colourless. Green sapphire could be of an intense green colour but more often than not these carry a tinge of yellow which invariably display an inferior appearance. The bluish green varieties resemble aquamarIne in appearances.
The purple sapphire is always of a violet blue inclined to purple or rose red. It is a mixture of the colours red and blue and could sometimes resemble the colour of amethyst or that of a rose red garnet.
Reference has already been made to pink sapphires under rubies and this variety will continue to be referred to as pink sapphires in this text, as the controversy is not yet resolved. Apart from these numerous colour varieties of corundum are also the colourless sapphires identified as white sapphires. When a single piece of corundum is found to have more than one colour, such stones are identified as parti-coloured sapphires. It is not surprising to find corundum having quite contrasting colours like blue and yellow, green and yellow or red and purple in a single specimen. Very often the colours are well demarcated but may sometimes merge into each other. 'Such bi-coloured gemstones are quite attractive when cut in numerous fancy shapes.