Photo of Rhodonite in Processed & Rough Form
Rhodonite is a mineral with a hardness of 6 out of 10 on the Mohs scale of mineral hardness [?]. These Triclinicly structured gems are made of manganese silicate, their full chemical compound being (Mn,Fe,Mg,Ca)SiO3.
Rhodonite is a silicate of manganese-iron-magnesium, a mineral of the Pyroxene group, with a triclinic crystal system.
It appears as rare tabular crystals, sometimes with rounded edges and wrinkled faces. It sometimes occurs as distinct, translucent to semiopaque crystals, but more often it is in compact, granular, ot crystalline masses of a patchy, pink, flesh red or brownish red color, often with blackish veining or spiderweb bands due to oxidation of manganese.
Its color is reddish pink, with thin veins or patches of gray to black.
It is hard, heavy, fragile, and has perfect prismatic cleavage (almost at right angles). It is insoluble in acids (unlike similar, softer rhodocrosite), and fuses fairly easily to red or brown glass.
It is formed by metamorphism (with addition of silica) of other manganese minerals, probably including rhodocrosite. It is a mineral typical of metamorphism of impure limestones (manganese and silica-rich), which are often the result of contact metasonic processes (skarns).
It is fairly widespread, mainly found in Sweden, Great Britain, the Soviet republics, India, Australia, South Africa, the USA, and Mexico.
Crystals and masses of rhodonite are common at Langban and Pajsberg (Sweden) and in the Urals (Sverdlovsk district, Russia). It is also found at Broken Hill (Australia), Chikla (India), Simsio (Finland), in Arrow Valley (New Zealand), and in Brazil, South Africa, and Japan. Also at Saint-Marcel (Val d'Aosta), Monte del Forno, and in Valle di Scerscen (Sondrio) and at Libiola and Gambaresa (Genoa), all in Italy. Fine fowlerite crystals are found in crystalline marbles at Franklin, New Jersey (USA).
The zinc-bearing variety of rhodonite is called fowlerite, containing up to 10% zinc oxide, frequently cut as a gem.
Other varieties of rhodonite include: alagite - a dull red, or green, altered rhodonite; alajites - a Mexican name for altered rhodonite.
It is often confused with rhodocrosite, bustamite, and thulite.
Manganese spar is a general term for both minerals, rhodonite and rhodochrosite.
Why is Russian Rhodonite considered the finest?
Ural Mountain rhodonite from Russia shows exceptional deep pink color and distinctive black veining patterns. Used historically in Russian imperial artwork and the Fabergé workshops, these specimens set the quality standard for ornamental material.
What causes the black patterns in Rhodonite?
The characteristic black veining comes from manganese oxide inclusions. Well-distributed patterns enhance value, particularly in ornamental pieces. Some collectors specifically seek specimens with dramatic black-on-pink patterns.
Why are transparent Rhodonites so rare?
While most rhodonite is opaque to translucent, rare transparent crystals suitable for faceting do exist, mainly from Australia and Brazil. These gem-quality specimens command premium prices due to their extreme rarity.
Does Rhodonite change color over time?
Surface oxidation can cause darkening, creating additional black areas. Quality specimens should be stored away from moisture and excessive heat. Some collectors value the natural aging process that creates more contrast.
How is Sweet Home Mine Rhodonite different?
Colorado's Sweet Home Mine produces distinctive rhodonite crystals with exceptional form and clarity. These specimens often show better crystallization than material from other localities and are highly prized by collectors.
Why do some pieces fluoresce?
Some rhodonite shows red fluorescence under ultraviolet light, particularly specimens with high manganese content. This property can help identify genuine material but doesn't significantly affect value.
What makes Fowlerite variety special?
Fowlerite is a zinc-rich variety of rhodonite, typically showing better crystal form and transparency. Found mainly in Franklin, New Jersey, these specimens are particularly valued by mineral collectors for their unique chemistry and appearance.
The specific gravity [?] for Rhodonite is 3.6, its refractive index [?] is 1.71-1.73, and its double refraction [?] is 0.014.
History
Rhodonite derives its name from the Greek "rhodon," meaning "pink" or "rose red" (like rhodocrosite).
Industrial Usages
The translucent to semiopaque polycrystalline form of rhodonite is cut en cabochon or shaped into beads, which can take a good polish. It is also used as an ornamental decorative element like inlay.
Rare transparent crystals have also been faceted into gems for collectors and connoisseurs. Facetable crystals are rare, but show a beautiful red, and have prismatic cleavage. Ornaments made of massive rhodonite are more common and are particularly handsome when they are veined by manganese oxides.
It is used in the art trade and occasionally as an ore of manganese.
Rhodonite has a somewhat low value compared with other ornamental materials, but faceted crystals are highly prized as collectors' pieces. It has neither been imitated nor produced synthetically.
You May Also Like...
Kunzite: Kunzite is the pinkish lilac variety of the spodumene. These crystals or stones have a light pink hue because they constrain, traces manganese. Kunzite was first discovered in California in the early 20th century, and is known for its pleochroism. Its been noted that prolonged exposure to uv or solar lighting will diminish this stones color. This stone is generally sought after for its properties (read full)
Phosphophyllite: Phosphophyllite is a very rare mineral, a hydrated zinc iron manganese phosphate with a monoclinic crystal system. It appears as long prismatic or thick tabular crystals. It is colorless to deep bluish-green. Polysynthetic twinned crystals are common. It is semi-hard, light, with excellent prismatic cleavage. Translucent to transparent with vitreous luster. It turns gray and loses water when hea (read full)
Rhodochrosite: Rhodocrosite is a manganese carbonate, a mineral of the calcite series with a hexagonal crystal system. It is isomorphous with calcite and siderite. It occurs as semitransparent, rhombohedral crystals with poor luster, frequently saddle-shaped, growing into druses, or as concretionary masses, sometimes with irregular, contorted veining. It has low hardness and perfect rhombohedral cleavage. Norm (read full)
Spessartine: Spessartine is the manganese-aluminum variety of Garnet, belonging to its sub-group of aluminum garnets. Garnets are a group of silicate minerals that all crystallize in the isometric system and have the same chemical formula, but in a diversity of proportions, so garnets show up as different varieties, in a broad range of environments. Spessartine possesses the form typical of garnet crystals, w (read full)
Morganite: Morganite is a pale red-purple, rose, salmon to purplish red, slightly pink, cesium-bearing variety of Beryl. The Beryl group of silicates includes the important gem varieties emerald, blue aquamarine, pink morganite, and red and yellow beryl. The color of morganite is usually a soft pink without any overtones. It has glassy luster, like other beryls, but its pleochroism is not noticeable. The p (read full)
