Oregon Sunstone | Gemopedia

While feldspars are found throughout the world, they are rarely of gem quality. However, there is a very special feldspar variety known as sunstone found in south central Oregon. The Oregon sunstone is both gem grade and available in large enough sizes to yield cut stones for jewelry. The deposit is located in the region's rugged high desert where sunstone is embedded in ancient lava flows of an extinct volcano. As the lava weathers away or is broken up, Mother Nature releases the crystals for man to gather.
Alternate
Names
Aventurine Feldspar
Colors
Pale Pinkish Orange, Pink, Reddish Orange, Red-Orange, Deep Red With Red, Green, Blue Adventurescence

Oregon Sunstone Classification

Common Name

Oregon Sunstone

Species

Labradorite

Variety

Oregon Sunstone

Colors

Pale Pinkish Orange, Pink, Reddish Orange, Red-Orange, Deep Red With Red, Green, Blue Adventurescence

Alternate Names

Aventurine Feldspar

Gemstone Groups

Feldspar

Key Separations

RI, birefringence, optic character and magnification.

Comments

Oregon Sunstone Optical Properties

Transparency

Translucent - Opaque

Refractive Index

1.563-1.572

Birefringence

0.009

Optic Character

Biaxial

Optic Sign

Positive

Polariscope Reaction

Doubly Refractive (DR)

Fluorescence

SWUV: Inert to moderate red
LWUV: Inert to moderate violet

CCF Reaction

Pleochroism

Dichroic, strong red and green

Dispersion

Strength: none

Comments

Oregon Sunstone Chemistry & Crystallography

Chemical Name

potassium, sodium or calcium silicate

Chemical Formula

NaAlSi3O8 or CaAl2SiO8

Synthesis

Crystal System

Triclinic

Classification

Silicate

Nature

Natural

Crystallinity

Crystalline

Comments

Oregon Sunstone Characteristic Physical Properties

Hardness

6

Streak

White

Specific Gravity

2.67-2.72 Typical:2.67

Toughness

Poor

Inclusions

Oregon sunstone contain tiny orange or yellow copper platelets or hematite platelets and stones might display adventurescence. Parting is common in this material.

Luster

Vitreous

Stability

Good

Fracture

Uneven, Splintery

Cleavage

Perfect, in two directions

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