having taken the RI reading multimal times of 1.506 this gives me a choice of 3 topaz, beryl or tourmaline.
The SG reading I got was 3.65
The colour of the stone is light pink
Clarity is vvs
I am right in thinking that this could be a synthetic gem
Hi Tony, If you work out the Birefringence of the RI this should directly point to which gemstone you have certainly close enough
Thank you for your reply I will go and do as you say and let you know the results many thanks
Regards Tony
If the gem is Singly Refractive then there won’t be a Bi-refringence … and that fact alone would rule out topaz, beryls, and tourmalines as they are Doubly Refractive. Additionally, very few Natural topaz, beryls, and tourmalines are VVS, so with no bi-refringence (SR) and VVS, with an RI of 1.506 … you would most likely have man made glass!! ;)) Don’t forget to do UV testing and magnetic testing. These are often helpful clues. Glass won’t be pleochroic using the Dichroscope as well. See if you can verify that the stone is Singly Refractive with your Polariscope … don’t get fooled by ADR though (Anomalous Double Refraction). Good luck with your gem ID. 
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Hi just to clarify with using the polariscope don’t just take the reading in one direction make sure you roll the stone on another side to check. if you place a gemstone that is double refractive on the polariscope and have it sitting directly down the C-Axis it will show as singly refractive gem 
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