Rhodonite

 

Rhodonite is a manganese inosilicate stone which belongs to the silicate mineral group. It’s easily identified and well known for its distinctive and attention getting appearance. This stone has a main coloring of pink or rose-red tones with accents of black or brown veins and dendrites. The name of this manganese inosilicate stone comes from the Greek word “rhodo,” which means rose.

Rhodonite's pink to red color is produced by manganese ions. The black veins and dendrites are actually manganese oxides that have formed through mineral alteration. Mineral alteration is the chemical or structural transformation of one mineral into a different mineral or mineral make-up due to changes in temperature, pressure, fluid composition, or environmental conditions

The differences in colors are attributed to the composition of this stone, being an inosilicate means that iron, magnesium and calcite often are in place instead of pure manganese. Rhodonite can also be found in brownish-red and black varieties with pink inclusions.

Rhodonite is commonly found in massive or granular forms that are most often translucent to opaque in appearance. It is a rare occasion when transparent, gem-quality material is found.  It normally will have a dull or earthy luster (an appearance like a flat looking paint) or may also be found with a vitreous or glassy luster with a nice sparkle. Both forms take a nice polish and are saved as collectibles or cut and made into  carved displays or cabochons for jewelry.

Rhodonite was originally only found in the Ural Mountains in Russia, but recently has been found in India, Mexico, Sweden, Africa, Madagascar, Brazil, Canada and the USA.

 

 

What is the Difference Between Rhodonite and Rhodochrosite ?

Rhodonite and Rhodochrosite ... Collectors can be confused as to which one is which. Both are pink and interesting collectibles ... so how do you tell them apart? Here are a few pointers for you.

The most obvious difference is rhodonite and rhodochrosite’s color patterns. Rhodonite has dark-colored, uneven bands or zones, but rhodochrosite has light-colored, mostly parallel color banding.

While both stones have perfect cleavage, the cleavage directions and shapes differ. Rhodonite’s cleavage is 2-directional and prismatic, while rhodochrosite’s cleavage is 3-directional and rhombohedral.

Differing Properties between Rhodonite and Rhodochrosite

Rhodonite is a Manganese silicate. Rhodochrosite is a manganese carbonate.

Rhodonite is a harder stone (5.5 – 6.5 mhos) than Rhodochrosite (3.5-4 mhos)

Rhodonite has a Triclinic crystal formation while Rhodochrosite has a trigonal crystal formation

Fluorescence is always present to some degree in Rhodonite while only sometimes present in Rhodochrosite

Rhodonite may be chatoyant but Rhodochrosite will never have chatoyance

Pleochroism of Rhodonite is pinkish-red to yellowish-red. Rhodochrosite is pale pink to pinkish-red or colorless. (Pleochroism is an optical phenomenon in which a substance has different colors when positioned at different angles with respect to a fixed position light source.)

When oxidation occurs, the manganese oxide in the rhodonite forms on most of the stone. Rusting (oxidation) after a longtime can make the entire stone look black.

Very few varieties of rhodochrosite will oxidize (this happens because of iron inclusions). The stone does not turn black from the oxidation, but instead it changes to a darker pink color.