Thulite | Gemopedia

Thulite is the translucent to opaque pink variety of zoisite, which is often mottled or streaked with gray or white quartz. The name thulite is derived from its discovery location, Norway, which was once called Thule. This gem is also called rosaline. Thulite is often cut en cabochon for jewelry manufacture or carved into ornaments.
Alternate
Names
Rosaline, Unionite
Colors
Pink To Red, Often With Mottled, Streaked With Gray, White

Thulite Classification

Common Name

Thulite

Species

Zoisite

Variety

Thulite

Colors

Pink To Red, Often With Mottled, Streaked With Gray, White

Alternate Names

Rosaline, Unionite

Gemstone Groups

Epidote

Key Separations

refractive index, appearance and SG

Comments

National gemstone of Norway. RI might be as low as mid 1.50s due to impurities

Thulite Optical Properties

Transparency

Translucent - Opaque

Refractive Index

1.691-1.7
Tolerance:(+0.005/-0.005)

Birefringence

0.008-0.013

Optic Character

Biaxial

Optic Sign

Positive

Polariscope Reaction

Doubly Refractive (DR)

Fluorescence

SWUV: Inert
LWUV: Inert

CCF Reaction

Pleochroism

Unobservable

Dispersion

Strength: weak fire Value: 0.021

Comments

Thulite Chemistry & Crystallography

Chemical Name

calcium aluminum silicate hydroxide

Chemical Formula

Ca2Al3(SiO4)3(OH)

Synthesis

Crystal System

Orthorhombic

Classification

Silicate

Nature

Natural

Crystallinity

Crystalline to Aggregate

Comments

Thulite Characteristic Physical Properties

Hardness

6-7

Streak

White

Specific Gravity

3.1-3.45 Typical:3.35

Toughness

Varies

Inclusions

Thulite has white veining is due to calcite and the pink color is due to manganese.

Luster

Vitreous

Stability

Good

Fracture

Conchoidal, Uneven

Cleavage

Perfect, in one direction, Good, in one direction

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