aMETRINE

Emerald cut ametrine pendant

Variety:  Ametrine
Species:  Quartz
​​Mohs Hardness:  7 out of 10
Color:  Bicolor combination of purple and orange hues
RI:  1.544 to 1.553 (very constant)
Birefringence:  0.009
SR/DR/AGG:  DR
Clarity Type:  Type II
Optic Character:  Uniaxial positive.  Might show a bull's eye or Airy's spiral optic figure and Brazil law twinning under crossed polarizing filters.
Pleochroism:  Very weak.  Different tones of yellow and orange, different tones of purple and reddish purple
Spectrum:  Not diagnostic
Fluorescence:  Generally inert.
SG:  2.66 (+0.03 / -0.02)
Routine Treatments:  None
Additional Enhancements:  Heating, iraddiation

ametrine Facts

Ametrine and diamond ring

Ametrine is a bicolor variety of quartz that has zones of purple (amethyst) and golden yellow (citrine) that border one another within the same gem crystal.

Amethyst + Citrine = Ametrine
​
The Anahi mine in Bolivia is the world's only commercial source of ametrine.  It has been producing ametrine since the 1600s and is still active today.

All photos courtesy of Scott Papper, GG, ASA, CMA, RGA, AJP, CMSP, CSSP