Sunstone

Member of the feldspar group

Sunstone Shop

Synonyms and trade names: Aventurine feldspar, occasionally heliolite

Ungewöhnlich transparenter Sonnenstein aus Indien unusually transparent specimen from India
Unusually transparent sunstone from India

Can be confused with: so-called goldstone, a man-made glass with included copper.

goldfluss
Goldstone

Localities: most sunstone comes from India, East Africa and North America.
A deposit in Telemark, Norway, no longer plays a major role in the international gemtrade.
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sonnenstein sunstone indien indiasonnenstein sunstone indien india

Sunstones from India

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Three distinctly diverse sunstones from Tansania

Sunstone from Oregon, USA, is highly coveted (and paid for) by gem connoisseurs and collectors

oregon sunstoneoregon sunstoneoregon sunstone

oregon sunstoneoregon sunstoneoregon sunstone

Oregon Sunstone

In India one occasionally finds sunstones with good asterism (star effect).

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Star sunstones

Handling: feldspar has perfect cleavage, so set and wear with care. Do not clean ultrasonically!

Sunstone Shop

Gemmological Properties of Sunstone

Formula:
(Ca,Na)((Al,Si)2Si2O8)
Crystal system:
triclinic
Mohs hardness:
6 - 6.5
Specific gravity:
2.63 - 2.66
Refractive index:
doubly refractive 1.533 - 1.552
Max. Birefringence:
0.009
Dispersion:
none
Pleochroism:
none
Lustre:
vitreous
Cleavage:
perfect
Fracture:
uneven conchoidal or steplike
Colour:
colourless to orange-brown with orange, reddish or brown inclusions of copper