SUNSTONE
Sunstone’s phenomenal varieties show a distinct and lively glitter called aventurescence.
Overview
ABOUT SUNSTONE
Diamond forms under high temperature and pressure conditions that exist only about 100 miles beneath the earth’s surface. Diamond’s carbon atoms are bonded in essentially the same way in all directions. Another mineral, graphite, also contains only carbon, but its formation process and crystal structure are very different. Graphite is so soft that you can write with it, while diamond is so hard that you can only scratch it with another diamond.
Sunstone Description
FELDSPAR
Sunstone is a member of the feldspar group of minerals.
ADVENTURESCENE
Sunstone can have a sparkly, metallic-looking luster caused by flat, reflective inclusions.
OREGON
Oregon sunstone is a transparent feldspar with glittery copper inclusions.
FACTS
Mineral: Feldspar
Chemical composition:
Orthoclase - KAlSi3O8
Oligoclase and labradorite - solid solution between NaAlSi3O8 and CaAl2Si2O8
Color: Yellow, green, red, red-brown, colorless
Refractive Index:
Orthoclase sunstone - 1.518 to 1.526
Oligoclase sunstone - 1.537 to 1.547
Labradorite sunstone - 1.559 to 1.568
Birefringence:
Orthoclase - 0.005 to 0.008
Oligoclase and labradorite - 0.007 to 0.010
Specific Gravity:
Orthoclase - 2.58
Oligoclase - 2.65
Labradorite - 2.70
Mohs Hardness: 6.0 – 7.2
TREATMENTS
There are a number of processes used to alter the color, apparent clarity, or improve the durability of gems.
SYNTHETICS
Some gemstones have synthetic counterparts that have essentially the same chemical, physical, and optical properties, but are grown by man in a laboratory.
IMITATIONS
Any gem can be imitated—sometimes by manmade materials or by natural materials chosen by man to impersonate a particular gem.
Why We Love This Gemstone
1
GLITTERY
Reflective inclusions in sunstone’s phenomenal varieties cause a distinct and lively glitter called aventurescence.
2
NATURAL
Oregon sunstone’s colors don’t result from treatment. The gem’s all natural and it’s mined in the United States.
3
“SPINEL RED”
Red-colored Oregon sunstone is often marketed to consumers as “spinel red.” Its vivid hue rivals spinel and even ruby.
QUALITY FACTORS
The following factors combine to determine a sunstone’s value.
COLOR
CLARITY
CUT
CARAT WEIGHT
SUNSTONE QUALITY FACTORS: THE COMPREHENSIVE GUIDE
RESEARCH
Explore sources, gemological research, and the role of gems in history.
.jpg "Mixed-cut Oregon sunstone")
Duncan Pay, Robert Weldon, and Kevin Schumacher , Oct 23, 2013
RECOMMENDED READING
Feldspar Mineralogy
Ribbe, P. H
