Andesine Value, Price, and Jewelry Information

Andesine By Dave Dyet (Own work) [Public domain], via Wikimedia Commons

Andesine

Andesine Information

Data Value
Name Andesine
Is a Variety of Feldspar
Colors Red, honey-red, pink, orange, yellow, champagne, golden, green, white, gray
Crystallography Triclinic.
Refractive Index 1.543-1.551
Hardness 6 to 6.5
Fracture Subconchoidal to uneven
Specific Gravity 2.65-2.69
Birefringence 0.008
Cleavage Excellent 2 directions
Luminescence Present Yes
Luminescence Type Fluorescent, UV-Long, UV-Short
Transparency Transparent to opaque.
Optics

α = 1.543; β = 1.548; γ = 1.551. Biaxial (+/-); 2V= 76-86°.

Optic Sign Biaxial +, Biaxial -

Comments

These feldspars are rarely encountered in gem form. Their occurrence is widespread throughout the world, in a great variety of rock types and environments, but in most cases transparent crystals are rare.

In many cases faceted gems are identified as a feldspar in the plagioclase series, but the finder does not have the instrumentation needed to pin down the species. This is accomplished by a combination of optical and X-ray analysis. A few plagioclase gems have been well characterized, however, and reported in the literature.

Name

Andesine is named after the Andes Mountains of South America.

Occurrence

Andesine is known from many localities, including California; Utah; Colorado; South Dakota; Minnesota; New York; North Carolina; Colombia; Argentina; Greenland; Norway; France; Italy; GermanY; South Africa; India; and Japan.