Color changing of corundum

Jewelry Discussion
1

Hi, I have some corundum lab alexandrites, those are sold by
(lab)thaigem.com in the eBay auction. Those price is about $1 per
carat. The color change is from light-blue purple to red purple. The
Red purple color is clear and strong, but the light-blue is far from
ideal.

I heard that there are better color change corundum ones, which have
also clear and strong blue color. But I’ve never seen such ones.

Does anybody know or have apparently better color change ones from
blue to red? What is the difference between my lab alexandrites and
better ones?

I also want to know about hydrothermal chrysoberyl lab alexandrite. Is
the color change different between cheep and good(expensive) ones?

Thank you,

Takashi Tomoeda
@Takashi_Tomoeda

2 
I also want to know about hydrothermal chrysoberyl lab alexandrite.
Is the color change different between cheep and good(expensive)
ones?

I know nothing about created alexandrite except that the best is
probably sold by J.O. Crystal Co. in Long Beach, CA, Ph: 562-437-0736,
web: www.ramaura.com. Judith Osmer, the owner of J.O. Crystal, is the
creator of Ramaura ruby, the best synthetic ruby available, but the
company also sells Nicholas created alexandrite and Empress cultured
emerald.

Beth

3

Hi I can answer some of your questions about alexandrites and
corundum. First proper Alexandrite is green to red or a blue/green to
red. As far as color change corundum I can answer you on the real
stuff. Real CC stones I have had have changed from orange to red,
green to orange, blue to purple, green to yellow,yellow to golden/
light orange, green to reddish ect.

I don’t know about the real synthetic alexandrites other than they
have some created especially for use in YAG lasers (they can tune the
wavelengths). the ones that don’t turn out they sell to cutters.

Alicia Miller

4

Takashi, I believe what you are referring to here are synthetic color
change corundum (alexandrite shouldn’t be used in this description as
there is now synthetic alexandrite available and it can get
confusing). Most of the synthetic material I have seen exhibits the
colors you are talking about. I haven’t ever seen anything that has a
really strong blue color. In natural material, on the other hand,
there is a quite a range of blue visible in color change material.
Perhaps you should look into natural material.

Daniel R. Spirer, G.G.
Spirer Somes Jewelers
1794 Massachusetts Ave
Cambridge, MA 02140
617-491-6000
@spirersomes
www.spirersomes.com