Humans and Birds and Color, Oh My!

Posted by & filed under Alexandrite.

rough alexandrite from omi gems

I am really appreciative of the fact that we humans see in color. It’s easy to take for granted, because it’s like breathing. We open our eyes, we see color. Do you remember how The Wizard of Oz starts out, in black-and-white? No matter how many times I watch that movie, I still gasp when Dorothy lands in Oz and suddenly the world is almost blinding with color. When it comes to color, we really do live in Oz.

I think that’s why so many people love colored gemstones. Many of the every-day colors we encounter are muted, and we get so busy we don’t even notice them. But then you see a rich red ruby or an eye-popping pink sapphire, and the energy flows into your eyes and straight to your brain. Gemstones are color personified. Read more »

How Old are Kashmiri Sapphires?

Posted by & filed under Fancy Sapphire, Kashmiri Sapphire, Sapphire.

Omi Privee ring with Kashmiri sapphire

Most people understand that gemstones are from the earth, and that they have been there for a long time. But a long time is such an abstract concept. However, when Gübelin Gem Lab is able to give the age of a gemstone using radiometric dating, that abstract concept becomes very real. How long is a long time? Think in terms of millions of years, not hundreds of thousands.  Here is an excerpt from the May 12, 2016 issue of the Gübelin Newsletter #46, on determining the absolute age of Kashmiri sapphires.


Kashmiri sapphires determined to be 25 million years old

Last fall, for the first time ever, the absolute age of a high-value gemstone has been determined. Our geochemical specialist Klemens Link used radiometric dating on the in-house Laser Ablation ICPMS facility. The method and results are published in the latest issue of the Journal of Gemmology, Vol 34, Issue 8. Meanwhile, age determination is applied regularly in our lab on rubies and sapphires, supporting the distinction of African and Sri Lankan sapphires from the Burmese and Kashmiri ones.

The determination of the exact age of Kashmiri sapphires, however, was not yet undertaken, until the Gübelin Gem Lab initiated a research project jointly with Prof. C. Liu, and Dr. C. Zhang of the Institute of Geology and Geophysics, Chinese Academy of Sciences in Beijing. Zircon crystals included in samples from the Gübelin Reference Collection have now been analysed by LA-ICPMS in the Gubelin lab, and by high-resolution SIMS at the IGGCAS in Beijing. The respective uranium-lead ages are 26.8 (±3.8) million years, and 24.97 (±0.22)  million years, mutually confirming the results.

 

Omi Prive Kashmiri sapphireThis is exciting news for all of us at Omi Gems and Omi Privé. Our Kashmiri Sapphires are among our favorite gemstones. To be able to imagine them in terms of their real age makes them even more magnificent in our eyes.

The platinum Omi Privé ring shown on the left and at the top of this post features a 3.43 carat Kashmir Sapphire accented with French-cut tapered diamond baguettes and round brilliant-cut diamonds.

Color Play

Posted by & filed under Alexandrite, Spinel.

alexandrite with spinel

About a year ago, interesting colors of purple spinel started showing up in the market. Spinel comes in a beautiful range of reds, pinks, blues and purples, but until now I haven’t seen much of the intense purple you see in the photograph at the top. This deep, rich purple is very similar to the color of alexandrite when viewed in incandescent light. Read more »