Spurrite Value, Price, and Jewelry Information

By Trtrtr (original) [Public domain], via Wikimedia Commons

Spurrite

This attractive but rather rare mineral has seldom been cut as a gemstone. Polished slabs and rough material appeared in 1986 at a mineral show in substantial quantities, however. This material is Mexican, translucent to opaque, and medium to dark purple in color.

Spurrite Information

Data Value
Name Spurrite
Colors Gray, lavender-gray, purple.
Crystallography Monoclinic. Crystals anhedral; usually massive, granular.
Refractive Index 1.640-1.679
Luster Vitreous.
Hardness 5
Fracture Uneven to splintery
Specific Gravity 3.0
Birefringence 0.039
Cleavage Distinct 1 direction
Luminescence Not reported.
Luminescence Present No
Transparency Transparent to opaque.
Absorption Spectrum Not reported.
Formula

Ca­5Si2O8CO3

Pleochroism

Not reported.

Optics

a = 1.640; β = 1.674; γ = 1.679. Biaxial (-), 2V= 40°.

Optic Sign Biaxial -

Optics: a = 1.640; β= 1.674; γ=1.679.

Biaxial (-), 2V= 40°.

Occurrence: A contact mineral in limestones.

Crestmore, California; Tres Hermanes, New Mexico.

Scawt Hill, County Antrim, Ireland.

Velardena mining district, Durango, Mexico.

Comments: This attractive but rather rare mineral has seldom been cut as a gemstone. Polished slabs and rough material appeared in 1986 at a mineral show in substantial quantities, however. This material is Mexican, translucent to opaque, and medium to dark purple in color.

The hardness and tenacity are adequate for use as cabochons.

Name: After the American geologist, Josiah Edward Spurr.