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Rhodochrosite

 

Rhodochrosite

 

Discovered in 1813; IMA status: Valid (pre-IMA; Grandfathered)

 

Chemistry

 

 

Chemical Formula:

Mn2+CO3

 

Manganese Carbonate

Molecular Weight:

114.95 gm

Composition:

Manganese

47.79 %

Mn

61.71 %

MnO

 

Carbon

10.45 %

C

38.29 %

CO2

 

Oxygen

41.76 %

O

 

 

 

 

100.00 %

 

100.00 %

= TOTAL OXIDE

 

 

Classification

   

   

Mineral Classification:

Carbonates

Strunz 8th Ed. ID:

5/B.02-50

Nickel-Strunz 10th Ed. ID:

5.AB.05

 

5 : CARBONATES (NITRATES)
A : Carbonates without additional anions, without H
2O
B : Alkali-earth (and other M
2+) carbonates

Related to:

Calcite Group. Rhodochrosite-Siderite Series. Calcite-Rhodochrosite Series.

Members of Group:

Calcite Group: Calcite, Gaspéite, Magnesite, Otavite, Rhodochrosite, Siderite, Smithsonite, Spherocobaltite

Varieties:

Capillitite, Cobaltoan Rhodochrosite, Ponite, Sphaerodialogite, Zincorhodochrosite

Synonyms:

Carbonate of Manganese, Diallogite, Dialogite, Inca Rose, Manganese Spar, Raspberry Spar, Rhodochrolite, Rhodocrosite, Strömite, Torrensite, Villaurite

 

 

Crystal Data

   

   

Crystallography:

Trigonal - Hexagonal Scalenohedral

Crystal Habit:

Crystals rhombohedral {1011} or less commonly {0112}, then frequently rounded and composite; scalenohedral rare; thick tabular {0001}; prismatic [0001]. {1120} and {2131} often striated [1101]. Massive, coarsely granular; compact; columnar; crusts; stalactitic (with zoned growth rings); botryoidal.

Twinning:

On {1012}, contact and lamellar, then flattened

 

 

Physical Properties

   

 

Cleavage:

Perfect on {1011}; perfect rhombohedral. Parting on {0112} at times. Translation gliding with T{0001}, t[1010].

Fracture:

Irregular/Uneven, Conchoidal

Tenacity:

Brittle

Moh's Hardness:

3.5 - 4.0

Density:

3.40 - 3.60 (pure = 3.70) (g/cm3)

Luminescence:

None

Radioactivity:

Not Radioactive

Other:

Slightly soluble in water with the solubility rate increasing with the presence of CO2. Soluble with effervescence in warm acids.

 

 

Optical Properties

   

   

Color:

Pink, rose-red, cherry-red, yellow, yellowish gray, cinnamon-brown, may be banded; pale rose to colorless in transmitted light. Reds occur when the mineral has minimal iron content.

Transparency:

Transparent to Translucent

Luster:

Vitreous; Pearly in aggregates

Refractive Index:

1.596 - 1.816  Uniaxial ( - )

Birefringence:

0.2180

Dispersion:

n/a

Pleochroism:

Weak, Faint; deep red colored material may be faintly dichroic with absorption O greater than E

 

 

Occurances

   

   

Geological Setting:

A primary mineral in low- to moderate-temperature hydrothermal veins; in metamorphic deposits; common in carbonatites; authigenic and secondary in sediments; uncommon in granite pegmatites.

Common Associations:

Alabandite, Baryite, Braunite, Calcite, Dolomite, Fluorite, Friedelite, Garnet Group, Hausmannite, Manganite, Pyrite, Quartz, Rhodonite, Siderite, Sphalerite, Tephroite, Tetrahedrite

Common Impurities:

Fe, Ca, Mg, Zn, Co, Cd

Type Locality:

Cavnic Mine (Kapnikbánya), Cavnic (Kapnic; Kapnik), Maramures Co., Romania

Year Discovered:

1813

View mineral photos:

Rhodochrosite Mineral Photos and Locations

 

 

More Information

   

   

 

Mindat.org
Webmineral.com

 

 

Rhodochrosite is a member of the Calcite Group of minerals that includes Calcite, Gaspeite, Magnesite, Otavite, Rhodochrosite, Siderite, Smithsonite and Spherocobaltite. Although Rhodochrosite is found in shades of pink, red and orangish pink, each of these colors seems unique in the gem world.

Rhodochrosite was named in 1813 by German mineralogist Johann Ludwig Hausmann (1782 - 1859) from the Greek words rhodon meaning rose and chroma meaning color, referring to its color.

Some say the world's finest Rhodochrosite comes from the Sweet Home Mine near Alma, Colorado. The rare and spectacular pink to red crystals are in such high demand for mineral collections that faceted gems are even rarer. The Sweet Home Mine was recently closed, making mineral specimens and faceted gems from this location especially rare.

Other sources of Rhodochrosite include Argentina, Japan, Peru, Russia and South Africa. Agentina produces beautiful pink cabochons with intricate color designs. Peru has small beautiful crystals that could be faceted, but the gems would be very small. The Hotazel Mine of the Kalahari Manganese fields in South Africa produces deep red crystals suitable for faceting. Rhodochrosite from Russia can be found as deep pink to red cabochons and rarely as faceted gems. The cabochons from Argentina are quite common. Cabochons from Japan and Russia are rare. Faceted gems from the Sweet Home Mine in Colorado and the Hotazel Mine in South Africa are very rare and in very high demand.

Rhodochrosite gems for sale:

Rhodochrosite-006

Gem:

Rhodochrosite - Russia

Stock #:

RHODO-006-RU

Weight:

27.07 ct

Size:

22.54 x 15.10 x 7.92 mm

Shape:

Oval Cabochon

Color:

Orangish red

Clarity:

Translucent - SI

Origin:

Russia

Treatment:

None (natural)

Price:

$148.00  [ Make an offer ]

Pictures are of the actual gem offered for sale.
Gem images are magnified to show detail.

Rhodochrosite-005

Russian Rhodochrosite is not as well know as some of the other sources but makes for a beautiful cabochon. This rare gem glows with a unique Rhodochrosite color.


Rhodochrosite-002A

Gem:

Rhodochrosite - Argentina

Stock #:

RHODO-002-AR

Weight:

0.0970 ct

Size:

2.55 x 1.69 mm

Shape:

Round Brilliant

Color:

Pink

Clarity:

VS2

Origin:

Argentina

Treatment:

None (natural)

Price:

$20.00

Pictures are of the actual gem offered for sale.
Gem images are magnified to show detail.

Rhodochrosite-002B

This is a small beauty from an unusual location. Most Rhodochrosite from Argentina is the opaque type normally found as cabochons or mineral specimens.

 

Rhodochrosite-003

Gem:

Rhodochrosite - Peru

Stock #:

RHODO-003-PE

Weight:

2.34 ct

Size:

11.74 x 7.25 x 3.35 mm

Shape:

Pear

Color:

Pink

Clarity:

MI (translucent)

Origin:

Peru

Treatment:

None (natural)

Price:

$240.00    [ Make an offer ]

Pictures are of the actual gem offered for sale.
Gem images are magnified to show detail.

Rhodochrosite-003

This Rhodochrosite is true rarity because of its size and clarity considering its origin. Most Rhodochrosite from Peru is available as opaque cabochons or very small faceted gems. Although this gem is moderately included, the inclusions are small in scale, not large fractures, giving it a beautiful translucent glow of pink color.

 

Rhodochrosite-004

Gem:

Rhodochrosite - Colorado

Stock #:

RHODO-004-CO

Weight:

2.11 ct

Size:

7.66 x 5.43 x 4.55 mm

Shape:

Scissor Emerald

Color:

Pink

Clarity:

Eye clean - VS2

Origin:

Sweet Home Mine, Colorado

Treatment:

None (natural)

Price:

SOLD (but we have others)

Pictures are of the actual gem offered for sale.
Gem images are magnified to show detail.

Rhodochrosite-004

This beautiful gem is from the now closed Sweet Home Mine near Alma, Colorado, USA. It is mostly eye clean with just a couple hard to see inclusions. The color is very well saturated and very bright pink. This is the best Sweet Home Mine Rhodochrosite I have seen in a long time. This gem was faceted right here in Colorado!

 

Rhodochrosite-005

Gem:

Rhodochrosite - South Africa

Stock #:

RHODO-005-SA

Weight:

2.61 ct

Size:

11.22 x 7.19 x 5.10 mm

Shape:

Fancy; Elongated Trillion

Color:

Orangish red

Clarity:

Loupe clean

Origin:

Hotazel Mine, South Africa

Treatment:

None (natural)

Price:

SOLD (but we have others)

Pictures are of the actual gem offered for sale.
Gem images are magnified to show detail.

Rhodochrosite-005

Wow! This is the most intensely colored Rhodochrosite I have ever seen. This beautiful gem is from the Hotazel Mine in Northern Cape Province, South Africa. Its color is deep orangish red and very bright. This gem is very well faceted and polished - very high quality in a beautiful shape.

 

Rhodochrosite-001A

Gem:

Rhodochrosite - Colorado

Stock #:

RHODO-001-CO

Weight:

0.311 ct

Size:

3.92 x 2.76 mm

Shape:

Round Brilliant

Color:

Pink

Clarity:

Eye clean - VVS2

Origin:

Sweet Home Mine, Colorado

Treatment:

None (natural)

Price:

SOLD (but we have others)

Pictures are of the actual gem offered for sale.
Gem images are magnified to show detail.

Rhodochrosite-001B

This beautiful gem is from the now closed Sweet Home Mine near Alma, Colorado, USA. It is eye clean with very minor inclusions visible with a loupe. The color is a very bright, slightly peachy pink. It is a very nice example of Sweet Home Mine Rhodochrosite.

 

 


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