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| Childrenite
was named in honor of John George Children (1777 - 1852),
an English chemist and mineralogist.
| Discovered
in 1823;
IMA
status: Valid (pre-IMA; Grandfathered) |
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Chemistry
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|
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Chemical
Formula: |
Fe2+Al(PO4)(OH)2
• H2O
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Hydrated
Iron Aluminum Phosphate Hydroxide |
Molecular
Weight: |
229.83 gm
|
Composition: |
Aluminum |
11.74 % |
Al |
22.18 % |
Al2O3 |
|
Iron |
24.30 % |
Fe |
31.26 % |
FeO |
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Phosphorus |
13.48 % |
P |
30.88 % |
P2O5 |
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Hydrogen |
1.75 % |
H |
15.68 % |
H2O |
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Oxygen |
48.73 % |
O |
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|
100.00 % |
|
100.00 % |
= TOTAL OXIDE |
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Classification
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Mineral
Classification: |
Phosphates
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Strunz 8th
Ed. ID:
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7/D.14-10
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Nickel-Strunz 10th
Ed. ID:
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8.DD.20
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8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
D : With only medium-sized cations, (OH, etc.):RO4= 2:1
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Related
to: |
Childrenite-Eosphorite Series. The Fe2+ analogue of Eosphorite.
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Varieties: |
None
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Synonyms: |
None
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Crystal
Data
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Crystallography:
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Orthorhombic - Pyramidal
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Crystal
Habit:
|
As
equant to pyramidal crystals, may be short prismatic
along {001}, thick tabular on {010}, or platy on {100},
commonly doubly terminated, to 2 cm; in radiating groups
and fibrous crusts; massive.
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Twinning:
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May
show twinning on {100} and {001}, observed optically,
to give pseudo-orthorhombic symmetry; may be due to
oxidation.
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Physical
Properties
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Cleavage: |
Imperfect, Poor
on {100}
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Fracture: |
Conchoidal
to Uneven
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Tenacity:
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Brittle
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Moh's
Hardness: |
4.5 - 5.0
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Density:
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3.18 - 3.25 (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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Optical
Properties
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Color: |
White, Yellowish brown, Brownish black
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Transparency: |
Transparent
to Translucent |
Luster: |
Vitreous
to Resinous |
Refractive
Index: |
1.649 - 1.691 Biaxial ( -
) |
Birefringence: |
0.0270
- 0.0420 |
Dispersion: |
Strong;
r > v |
Pleochroism: |
X
= yellow; Y = pink; Z = pale pink to colorless.
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Occurances
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Geological
Setting: |
In
some complex granite pegmatites, typically a low-temperature
hydrothermal alteration product of primary phosphate
minerals.
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Common
Associations: |
Siderite,
Pyrite, Apatite, Quartz (Tavistock, England); Zinnwaldite,
Tourmaline, Akaolinite (Greifensteine, Germany) |
Common
Impurities: |
Ca,
Mn |
Type
Locality: |
Tavistock District, Devon, England, UK
|
Year
Discovered: |
1832
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View
mineral photos: |
Childrenite
Mineral Photos and Locations |
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More
Information
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|
Mindat.org
Webmineral.com
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Childrenite forms a series with Eosphorite,
Childrenite being at the Fe end of the series and Eosphorite
being at the Mn end. Both are very rare
gems, although Childrenite is much rarer than Eosphorite.
Childrenite is found as brown, yellowish brown
and golden yellow crystals. Facetable crystals
from Minas Gerais, Brazil are usually brown. Crystals
from other locations such as Cornwall, England; Greifenstein,
Germany and Custer, South Dakota, USA are not facet
grade.
(gem
photograph above courtesy of Jay Medici)
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Childrenite
gems for sale:
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Gem:
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Childrenite |
Stock
#:
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CHILD-001 |
Weight:
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0.1085
ct |
Size: |
3.01
x 2.09 mm |
Shape: |
Round |
Color: |
Light
Orangish Brown |
Clarity: |
Eye
Clean |
Origin: |
Minas
Gerais, Brazil |
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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An
extremely rare gem from Minas Gerais,
Southeastern region, Brazil with a very
bright orangish brown color.
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