Prasiolite | Gemopedia

A pastel dream, this variety of quartz boasts a beautiful soft green color. Sometimes called "green amethyst" or "lime citrine," prasiolite is rarely found in nature, so most material available on the market is produced by heating or irradiating amethyst or citrine. Prasiolite is an exciting gem in that it is readily available in large sizes with high transparency and great durability.
Alternate
Names
Green Quartz, "Greened Amethyst"
Colors
Green To Yellowish Green

Prasiolite Classification

Common Name

Prasiolite

Species

Quartz

Variety

Prasiolite

Colors

Green To Yellowish Green

Alternate Names

Green Quartz, "Greened Amethyst"

Gemstone Groups

Key Separations

Refractive index, birefringence, optic character and optic figure. A bull's-eye optic figure is determinative for quartz. The presence of Brazil-law twinning is a means of separating amethyst from scapolite.

Comments

Misnomer: green amethyst. Green color is rarely found naturally and most are irradiated and/or heat treated.

Prasiolite Optical Properties

Transparency

Transparent - Translucent

Refractive Index

1.544-1.553
Tolerance:very constant

Birefringence

0.009

Optic Character

Uniaxial

Optic Sign

Positive

Polariscope Reaction

Doubly Refractive (DR)

Fluorescence

SWUV: Inert
LWUV: Inert

CCF Reaction

Pleochroism

Dichroic, unobservable or weak, varying shades of body color

Dispersion

Strength: weak fire Value: 0.013

Comments

Prasiolite Chemistry & Crystallography

Chemical Name

silicon dioxide (aka silica)

Chemical Formula

SiO2

Synthesis

Crystal System

Trigonal

Classification

Silicate

Nature

Natural

Crystallinity

Crystalline

Comments

Prasiolite Characteristic Physical Properties

Hardness

7

Streak

White

Specific Gravity

2.64-2.69 Typical:2.66

Toughness

Good

Inclusions

Prasiolite is a type II clarity stone. Stones may contain crystals, negative crystals, liquid inclusions, two-phase inclusions and partially-healed fractures.

Luster

Vitreous

Stability

Good

Fracture

Conchoidal

Cleavage

None

Comments

JTV on Google+
0 Items
My Wish List
Close
Item
Description
Qty.
Price


Estimated Order Total:
0
Total Due Today:
0
Close
Item
Description
Qty.
Price


Page of 1