Joined: Tue Jan 29, 2008 8:55 am Posts: 236 Location: Paris - France
Dear Members,
I got this ring and wonder what these lines in the center stone could be. They are parallel and not curved. RI and birefringence fit with sapphire and the stone has no reaction under UV light.
First I thought of growth lines but could it also be rutile needles? I am not able to see this clearly under my bino as the lines appear only if the light penetrates the stone under a certain angle which is quite impossible to reproduce there. My 2nd question is if with these features, the stone could be a synthetic or treated (cobalt/berylium diffusion p.ex.).
Under other lighting conditions, the stone is quite dark blue with some intense blue reflections as those you can see in the lower part of the stone here even if the photo is quite bad as I tried to show the lines and not the reflections .
Hi Christel, nice ring! The "lines" you see in the sapphire are very common in the gems I mine. They can be silver, or gold, and we call them "silk". They are rutile, and they will often define the growth pattern in the sapphire. They can make the finished gem seem "sleepy", and this is one reason for heat treating the rough. If the cook is right, all the silk disappears, and the gem comes to life. From your photos, I'm seeing a natural, untreated stone. Barry.
Joined: Tue Jan 29, 2008 8:55 am Posts: 236 Location: Paris - France
Hi Barry, Thanks for your reply
I bought the ring this year during my holidays in Thailand and, as we all know, it's a place where a lot of treatments are done and are rarely disclosed correctly by the vendors so I was quite suspicious about the "nature" of this stone as I had only my loupe with me during the purchase.
Joined: Fri May 12, 2006 11:24 am Posts: 7523 Location: Rome, Italy
mrb wrote:
Hello , GIA says alternating color zones of blue and white are a Kashmir sapphire feature.
i'm sorry mrb but it's my understanding that feature doesn't exclusively belong to Kashmir sapphires, i saw that in many stones from other sources.....
According to the paper, it's not just alternating color zones, it's sharp zones of intense blue with milky white in between (which give it that distinctive velvety look). That sounds a bit more reasonable to me.
Just had to chime. Little off topic, but the bracelet on page 268 looks pretty comfy. Buckle-like, nice smooth taper, amazing, fantastic style inspiration.
I think I'll just gaze at the picture, until I really feel like buckling down to business and understanding the topic at bay here. Pictures........Pictures.........Dang, I'm feeling mentally lazy.
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