Blue Sapphire Jewellery Collection 2

Blue Sapphire Jewellery
Aamir Mannan.                                     
 BLUE STONES
                            SAPPHIRE
One of the most important spectra in the whole series for the practicing gemmologist is that of sapphire, for it only proclaims the species of the stone, but also reveals whether it be natural or synthetic. The spectrum, which is due to 

iron is seen at all strength in green sapphire and in varying strength in yellow sapphire as has been described above.In blue sapphires the bands are again very variable in strength. Australian sapphires show all three bands quite strongly. The band is an 'Ordinary Ray' band and therefore shows at maximum 
strength in the direction of the optic axis. passing light through a copper sulphate filter flask is here very helpful,enabling the 
observer to see any bands in the blue region with great clarity. A 'Polaroid' disc turned to the correct angle over the eyepiece of the spectroscope may also help to increase the apparent strength of the band.IT is well worth the gemmologist's while to practise the observation of this 

band, as it will save him much time and trouble in testing sapphire jewellery.