Photo of Sunstone in Processed & Rough Form
Sunstone is a mineral with a hardness of 6 out of 10 on the Mohs scale of mineral hardness [?]. These Triclinicly structured gems are made of sodium calcium aluminum silicate, their full chemical compound being Na(AlSi3O8) to Ca(Al2Si2O8).
In its raw form, sunstone forms as translucent to transparent crystals with distinct cleavage planes and a vitreous luster. The unpolished specimens display copper platelets that catch light even through the rough surface, creating scattered copper-red flashes. Once cut and polished, sunstone truly comes alive - skilled lapidaries often favor oval or cushion cuts that maximize the stone's aventurescence effect.
What are the defining optical properties?
Composition: Feldspar with copper inclusions Hardness: 6-6.5 Mohs Refractive Index: 1.525-1.539 Specific Gravity: 2.62-2.69 Distinctive aventurescence Pleochroism present
What causes the schiller effect?
Copper platelets produce red to gold flash Hematite creates reddish sheen Orientation affects flash intensity Size of inclusions impacts color Distribution determines pattern quality
What distinguishes Oregon material?
Oregon Sunstone: Copper content Larger clean gems possible Stronger color saturation More intense schiller Unique red-green dichroism Higher transparency possible
What determines quality grading?
Schiller intensity Base color strength Clarity level Size of specimen Pattern distribution Overall brilliance
What are key cutting considerations?
Orientation for best flash Inclusion pattern preservation Size versus effect balance Polish requirements Cleavage awareness Shape optimization
What indicates natural formation?
Random inclusion patterns Natural color zoning Growth structure presence Inclusion characteristics Surface feature analysis
What affects market value?
Schiller quality Color intensity Size availability Origin verification Treatment status Overall rarity
The specific gravity [?] for Sunstone is 2.65, its refractive index [?] is 1.52-1.54, and its double refraction [?] is 0.008.
History
Vikings reportedly used it for navigation in cloudy weather. Later prized by Native American tribes. Gained popularity in fine jewelry through Tiffany & Co. in the 1800s. Became Oregons state gem in 1987.
Industrial Usages
Sunstone is primarily used in jewelry and decorative objects. Its unique optical properties make it a popular choice for cabochons and beads.
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