Back to IGS | FAQ | Contact

Star cap tourmaline

I am speaking with a vendor about some material like this. He calls it star cap tourmaline. I’m not familiar with it at all, but it looks nice. I just want a bit more information on it. Is it natural this way or is it some sort of treatment? How should it be priced? This particular piece is 24ct. Can anyone help shed some light, please?


“Star Cap Tourmaline”, that’s a new one on me. Never heard of it.

Hi ElijahW36862. I have never heard of star cap tourmaline either. If it were to have a star, it would display asterism along the X-axis. Judging only by the picture, it looks like blue tigereye. Does it display a chatoyant effect when it 's moved? I would suggest checking refraction. Tourmaline should be 1.614 - 1.666. Tigereye (quartz) would be 1.544 - 1.553. What ever it is, it sure is pretty, but be careful what you pay for an unknown stone. I’ve got a box full of lessons learned!


I’ve done a little more digging. I think it’s likely a cat’s eye tourmaline. I found some pictures that are really close to how this stuff looks. I think the star cap name may be an error in translation.

1 Like

Hi, I’ve seen similar material as cats eye tourmaline. You should ask him to send a video of how chatoyant the material is.

Yes, agree this looks like cats eye tourmaline. The tubes that create the chatoyancy are visible and sometimes the stone is porous. Yes, you need a video to judge the eye. I don’t know of any process by which a synthetic stone like this could be produced, so it is almost certainly natural. As to value, you would have to find some sources that sell this. It is likely priced below faceted tourmaline. -royjohn

Some info in the first link and a nice image in the second. As for price I think they’re a bit special, try finding one for sale, so don’t under value them.

Cat’s Eye Tourmaline Gemstone Information - GemSelect

proxy-image (275×183) (