Gem identification

[GLbluegreen]

Hello PS friends. I have become fascinated with pink and red spinel's since discovering them on this forum. However, I have a pink gemstone that I bought several years ago in a different city than where I now live. I have purchased two pink spinel's recently from respected PS vendors and when I compare the color to that of the old pink stone I have they are very very similar. Problem is I never kept the paperwork on the old pink stone and I can't remember what I was told it was when I bought it. My mind keeps telling me it was a pink tourmaline for some reason, yet I can't be sure. Is there a way that I could get identification of it without sending it off to a lab ? It is set in a ring so don't know if that makes it more difficult to id or not. Any help would be appreciated .

 

[GLbluegreen]

It might help if I post a few pictures of the stone in question.

 

[PrecisionGem]

You can easily separate tourmaline from spinel with a home made polariscope. Spinel is single refractive, were tourmaline is double refractive. Use two polarizing lenses from sunglasses, one below the stone, one above, with light coming from the lense below. When you rotate the stone, if it looks the same, then it is single refractive. If it turns dark then light, then it is double refractive.

 

[GLbluegreen]

Thank you for the great idea. Would I still be able to do that with it in it's setting ? If I have any difficulty would a local gemologist be able to do that same test for me ?

 

[PrecisionGem]

If the setting is open on the back so that light can travel through the stone you can. Any gemoligist could also take a refractive index reading of the stone while it's in the setting as long as the prongs don't extend above the table of the stone, which it looks like they do not.