Chrome Tourmaline

Chrome tourmaline and trillion cut diamond ring in 18K gold
Chrome tourmaline and diamond ring
Variety:  Chrome
Species:  Tourmaline
​​Mohs Hardness:  7 to 7.5 out of 10
Color:  Intense green, bluish green, and yellowish green
RI:  1.624 to 1.644 (+/-0.005)
Birefringence:  Usually 0.018 to 0.020
SR/DR/AGG:  DR
Clarity Type:  Type III
Optic Character:  Uniaxial negative
Pleochroism:  Medium to strong, usually two tones of the gem's body color.
Spectrum:  Often not diagnostic
Fluorescence:  Varies
Chelsea Filter:  Will show flashes of red or orangy red under incandescent light
SG:  3.06 (+0.20 / -0.06)
Routine Treatments:  None
Additional Enhancements:  Heating, irradiation

Chrome Tourmaline Facts

Chrome tourmaline and trillion cut diamond ring in 18K gold
Chrome tourmaline and diamond ring


​Chrome tourmaline is usually an intense forest green, with hints of yellow or blue secondary hues.  Blue secondary hues are preferred over yellow.

Chrome tourmaline's vivid green coloration is caused by trace elements of chromium and vanadium.

Chrome tourmaline can be separated from regular green tourmaline via the Chelsea filter.  Under incandescent light, chrome tourmaline will show flashes of red or orangy red, due to its chromium content.

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Chrome Tourmaline Gallery

All photos courtesy of Scott Papper, GIA GG, AJP, CMA (NAJA)