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Rhodochrosite
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Discovered in 1813; IMA status: Valid (pre-IMA; Grandfathered)
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Chemistry
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Chemical
Formula: |
Mn2+CO3
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Manganese Carbonate
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Molecular
Weight: |
114.95 gm |
Composition: |
Manganese |
47.79 % |
Mn |
61.71 % |
MnO |
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Carbon |
10.45 % |
C |
38.29 % |
CO2 |
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Oxygen |
41.76 % |
O |
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100.00 % |
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100.00 % |
= TOTAL OXIDE |
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Classification
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Mineral
Classification: |
Carbonates
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Strunz 8th
Ed. ID:
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5/B.02-50
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Nickel-Strunz 10th
Ed. ID:
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5.AB.05
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5 : CARBONATES (NITRATES)
A : Carbonates without additional
anions, without H2O
B : Alkali-earth (and other M2+)
carbonates |
Related
to: |
Calcite
Group. Rhodochrosite-Siderite Series. Calcite-Rhodochrosite
Series.
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Members
of Group: |
Calcite
Group: Calcite, Gaspéite, Magnesite, Otavite, Rhodochrosite,
Siderite, Smithsonite, Spherocobaltite
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Varieties: |
Capillitite,
Cobaltoan Rhodochrosite, Ponite, Sphaerodialogite, Zincorhodochrosite
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Synonyms: |
Carbonate of Manganese,
Diallogite, Dialogite, Inca Rose, Manganese Spar, Raspberry
Spar, Rhodochrolite, Rhodocrosite, Strömite, Torrensite,
Villaurite
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Crystal
Data
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Crystallography:
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Trigonal
- Hexagonal Scalenohedral
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Crystal
Habit:
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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.
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Twinning:
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On
{1012}, contact and lamellar, then flattened
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Physical
Properties
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Cleavage: |
Perfect
on {1011}; perfect rhombohedral. Parting on {0112} at times.
Translation gliding with T{0001}, t[1010].
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Fracture: |
Irregular/Uneven,
Conchoidal
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Tenacity:
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Brittle
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Moh's
Hardness: |
3.5
- 4.0
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Density:
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3.40 - 3.60 (pure = 3.70)
(g/cm3)
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Luminescence:
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None
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Radioactivity:
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Not
Radioactive
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Other: |
Slightly soluble in water with the solubility rate increasing with the presence
of CO2. Soluble with effervescence in warm acids. |
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Optical
Properties
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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.
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Transparency: |
Transparent
to Translucent
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Luster: |
Vitreous;
Pearly
in aggregates
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Refractive
Index: |
1.596 - 1.816
Uniaxial ( - )
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Birefringence: |
0.2180
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Dispersion: |
n/a
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Pleochroism: |
Weak,
Faint;
deep red colored material may be faintly dichroic with absorption O greater than E
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Occurances
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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
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Common
Impurities: |
Fe,
Ca, Mg, Zn, Co, Cd |
Type
Locality: |
Cavnic Mine (Kapnikbánya), Cavnic (Kapnic; Kapnik),
Maramures Co., Romania |
Year
Discovered: |
1813
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View
mineral photos: |
Rhodochrosite
Mineral Photos and Locations |
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More
Information
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Mindat.org
Webmineral.com
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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.
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Rhodochrosite
gems for sale:
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Gem:
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Rhodochrosite
- Russia |
Stock
#:
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RHODO-006-RU |
Weight:
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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. |
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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.
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Gem:
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Rhodochrosite
- Argentina |
Stock
#:
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RHODO-002-AR |
Weight:
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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. |
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This is
a small beauty from an unusual location.
Most Rhodochrosite from Argentina is the
opaque type normally found as cabochons
or mineral specimens.
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Gem:
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Rhodochrosite
- Peru |
Stock
#:
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RHODO-003-PE |
Weight:
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2.34
ct |
Size: |
11.74
x 7.25 x 3.35 mm |
Shape: |
Pear |
Color: |
Pink |
Clarity: |
MI
(translucent)
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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. |
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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.
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Gem:
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Rhodochrosite
- Colorado |
Stock
#:
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RHODO-004-CO |
Weight:
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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. |
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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!
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Gem:
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Rhodochrosite
- South Africa |
Stock
#:
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RHODO-005-SA |
Weight:
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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. |
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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.
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Gem:
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Rhodochrosite
- Colorado |
Stock
#:
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RHODO-001-CO |
Weight:
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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. |
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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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