Aquamarine or Blue Topaz?

Hi all. I am a bench Jeweler, not a geologist. While I work with gemstones, there are questions like this I run into a lot. Can someone guide me on this question? Vermont Jeweler, David Pennant. Thanks!


One easy way to tell is by looking through a loupe and checking for double refraction. If you can see doubling of the facet lines very clearly, then the stone is topaz. If not, the stone is most likely aquamarine

Hope this helps!

Phoebe Shang, GG
IGS Team Member


While certainly its a possible way. DR in topaz I am almost always not able to spot. So I usually try to understand the color of the stone, along with inclusions. Topaz from Srilanka, Brazil can have rutile needles. The color of an aquamarine; if greenish, yellowish, can be an aquamarine. However the best way to test 100% would be by checking its RI, with an refractometer.