PRASIOLITE

Prasiolite and diamond necklace

Species:  Quartz
​​Mohs Hardness:  7 out of 10
Color:  Green to yellowish green, usually light in tone and saturation.
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:  Weak to moderate purple and reddish purple
Spectrum:  Not diagnostic
Fluorescence:  Generally inert.
SG:  2.66 (+0.03 / -0.02)
Routine Treatments:  Heating and irradiation

Prasiolite Facts

Prasiolite and diamond ring, in sterling silver

Prasiolite is the green variety of quartz.​

Its name is derived from the Greek word prason meaning "leek" and lithos meaning "stone".

Prasiolite is sometimes incorrectly referred to as green amethyst or lime citrine.

Prasiolite is rarely found in nature, and is usually the result of heating amethyst or citrine.

Since its discovery in the 1950s, Brazil is still the only known source producing gem quality natural prasiolite.