Rhodonite Value, Price, and Jewelry Information

Ranging in color from pink to a fine rose red, rhodonite is a popular material for jewelry and decorative objects. Faceted rhodonite has an intense, beautiful color, but this material has a reputation as one of the most difficult gemstones to cut.

Rhodonite Value

The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.

Rhodonite Information

Data	Value
Name	Rhodonite
Crystallography	Triclinic. Crystals tabular; massive, cleavable. granular.
Colors	Rose red, pink, brownish red; often veined by black Mn oxides.
Luster	Dull (massive) to vitreous.
Polish Luster	Vitreous
Fracture	Conchoidal. Brittle (crystals); tough if compact.
Hardness	5.5-6.5.
Toughness	Good in aggregate, poor in transparent stones
Specific Gravity	3.57-3.76 (massive): 3.67 in crystals.
Cleavage	Perfect 1 direction.
Luminescence	Dull red to inert. Medium dull red in SW (Hungary), dull deep red in LW (Langban. Sweden).
Spectral	Broad band at 5480, strong narrow line at 5030, diffuse weak band at 4550. May also see lines at 4120 and 4080.
Transparency	Transparent to Opaque.
Formula	MnSiO3 (+ Ca to maximum of 20%).
Pleochroism	Weak, but may be distinct: yellowish red/ pinkish red/pale yellowish red.
Optics	Biaxial (+), 2V=63-76°. Shadow edge at 1.73 in massive varieties. See “Identifying Characteristics” below.
Etymology	From the Greek rhodos for “rosy,” in allusion to the color.
Occurrence	In manganese-bearing ore bodies or in their vicinity.
Inclusions	May contain black dendritic inclusions of manganese oxide

Comments

Perfect cleavage that develops extremely easily makes transparent, facetable rhodonite quite delicate. Thus, faceted stones are rare. However, gem carvers can make cabochons, goblets, figurines, and other objects from massive material with attractive black dendritic, “tree-like,” veins.

Massachusetts declared rhodonite its official state gemstone.

Identifying Characteristics

You may find cut bustamite gems erroneously labelled as rhodonites. They have a similar but paler color. However, bustamite’s distinctly lower refractive indices should prove diagnostic.

Cut pyroxmangite gems also resemble rhodonites. Their optic sign and birefringence are diagnostic.

Fowlerite is a zinc-bearing variety of rhodonite.

Some rhodonites found in Brazil may show chatoyancy.

Optics

	α	β	γ	Birefringence	Density	2V
Honshu, Japan	1.726	1.731	1.739	0.013	3.57	64°
Pajsberg, Sweden	1.720	1.725	1.733	0.013	3.62	75°
Broken Hill, New South Wales, Australia	1.723-1.726	1.728-1.730	1.735-1.737	0.011-0.013	3.68-3.70	74°
General	1.711-1.738	1.716-1.741	1.723-1.752	0.011-0.014	3.57-3.76	63-76°

Enhancements

No known synthetics. This material usually receives no treatments. Dyeing is rare.

Sources

Russia (Sverdlovsk) produces very fine and rich, massive, pink and rose-colored material. British Columbia, Canada yields fine rhodonite similar in appearance to the Russian material. However, the best material from British Columbia has a translucent, deep rose-pink color. Some fine, pink material from Bella Koola, British Columbia features black dendritic patterns.

Australia produces fine transparent crystals and massive material at Broken Hill, New South Wales. Gemmy rhodonite grains embedded in galena (lead sulfide) at this location are distinctive. Rhodonites can occur here with pyroxmangite and bustamite, which can grow in crystals up to 100 cm long!

Other notable gem sources include:

• Honshu, Japan: facetable material.
• Vermland, Sweden: good color gem material.
• Daghazeta, Tanzania: fine-quality massive material.
• United States: California; Colorado; Massachusetts; Montana; Franklin, New Jersey.
• Brazil; Cornwall; England; Mexico; Peru; South Africa.

Stone Sizes

Massive rhodonite pieces from various localities are available. However, extremely rare facetable gem material comes from crystals found primarily in Australia and Japan ranging in size from 2-3 carats. A few larger stones may exist.

Care

Although pieces cut from massive material have greater wearability, both faceted gems and carved objects require special care. Due to rhodonite’s relatively low hardness, avoid mechanical cleaning such as steam or ultrasonic processes. Instead, use a soft brush, mild detergent, and warm water for cleaning. Store your rhodonites separately from other stones to avoid contact scratches. Use protective settings for your jewelry stones and avoid physical blows, due to their cleavage and fracture potential. Consult our gemstone jewelry cleaning guide for more recommendations.

by Dr. Joel Arem