Bustamite Value, Price, and Jewelry Information

BUSTAMITE: Broken Hill, New South Wales, Australia (2.6). Photo © Joel E. Arem, PhD, FGA. Used with permission.

Bustamite

Bustamite is very similar in appearance and properties to rhodonite. The Japanese crystals are very rich in Mn. The color, when fresh, is paler than rhodonite. Bustamite may also be fibrous, and then yields fine catseye gems, but these are extremely rare. Faceted Bustamite are very attractive, especially in the pinkish shades, but stones over 1-2 carats are very rare collector items. The cleavage makes cutting difficult and wear ill advised.

Bustamite Information

Data Value
Name Bustamite
Colors Pale pink to brownish red.
Crystallography Triclinic. Crystals tabular, usually rounded and rough; massive.
Refractive Index 1.662-1.707
Luster Vitreous.
Hardness 5.5 - 6.5
Fracture Conchoidal
Specific Gravity 3.32-3.43
Birefringence 0.014-0.015
Cleavage Perfect 1 direction, good 1 direction
Stone Sizes Faceted gems are usually small, less than 5 carats, and mostly in the 1-2 carat range. Catseyes are also known, up to about 5 carats.
Luminescence None
Luminescence Present No
Transparency Transparent to opaque.
Absorption Spectrum Not diagnostic.
Phenomena Chatoyancy (extremely rare).
Formula

(Mn, Ca)3Si3O9
Pleochroism

Weak; rose red/ orange/ orange
Optics

a = 1.662-1.692; β = 1.674-1.705; γ = 1.676-1.707. Biaxial (-), 2V = 30-44°.
Optic Sign Biaxial -

OPTICS: a = 1.662-1.692; β = 1.674-1.705; γ = 1.676 -1.707

Biaxial (-), 2V = 30-44°.

OCCURRENCE: Manganese ore bodies, usually of metasomatic origin.

Cornwall, England; Långban, Sweden.

Franklin and Sterling Hill, New Jersey: in fine crystals.

Iwate and Yamagata prefectures, Japan: gemmy crystals.

Broken Hill, N.S.W., Australia: this material has high Mn content, in crystals up to 2 x 10 cm; S.G.= 3.41, 2V = 39°, a= 1.688, β = 1.699, γ = 1.703, Birefringence 0.015.

COMMENTS: Bustamite is very similar in appearance and properties to rhodonite. The Japanese crystals are very rich in Mn. The color, when fresh, is paler than rhodonite. Bustamite may also be fibrous, and then yields fine catseye gems, but these are extremely rare. Faceted Bustamite are very attractive, especially in the pinkish shades, but stones over 1-2 carats are very rare collector items. The cleavage makes cutting difficult and wear ill advised.

NAME:  After the discovery of the mineral. M. Bustamente.

 

by Joel E. Arem, Ph.D., FGA