Prasiolite

Related: Quartz Varieties

AgateAmethystAmetrineAventurineBloodstoneCarnelianChalcedonyChrysopraseCitrineHawk's EyeOnyxRock CrystalRose QuartzSmoky QuartzTiger's Eye

Key Differentiators

• Pale leek-green to mint green color distinct from deeper greens of tourmaline or peridot
• Quartz RI 1.544–1.553 and SG 2.65 — much lighter than peridot (SG 3.34) or tourmaline
• Weak pleochroism (pale green / colorless)
• All commercial material is heat-treated or irradiated amethyst — color may fade under prolonged UV
• Inert UV fluorescence in both LW and SW

Common Simulants

• Green Tourmaline: Tourmaline has much higher RI (1.624–1.644) and strong dichroism. SG 3.06 vs prasiolite 2.65. Color is typically more saturated. RI separates cleanly.
• Peridot: Peridot RI 1.654–1.690, SG 3.34 — significantly heavier and higher RI. Birefringence 0.036 means facet doubling visible under loupe. Strong yellowish-green color.
• Green Beryl: Green beryl RI 1.577–1.583, SG 2.72 — slightly higher RI and SG than prasiolite quartz. Uniaxial negative vs prasiolite uniaxial positive.
• Green Glass: Glass is singly refractive (isotropic), may have gas bubbles or swirl marks under magnification. RI variable but no birefringence.

Commonly Confused With

Commonly confused with: Green Tourmaline, Peridot.

Treatments

• Heat Treatment (amethyst → green)
• Irradiation (amethyst → green)

Price Context

Price context is approximate. GemID is not an appraisal tool. Results are indicators, not certified valuations.

About Prasiolite

Prasiolite is the pale green variety of quartz produced commercially by heat-treating or irradiating amethyst from Brazil. Naturally occurring prasiolite is extremely rare. The color is typically a gentle leek-green or mint and lacks the intensity of tourmaline or peridot.