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Santabarbaraite
A valid IMA mineral species
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About Santabarbaraite
Formula:
Fe3+3(PO4)2(OH)3 · 5H2O
Colour:
Orange, orange brown, yellowish-brown
Lustre:
Sub-Vitreous, Resinous, Waxy, Greasy
Specific Gravity:
2.42
Crystal System:
Amorphous
Name:
Named in 2000 by Giovanni Pratesi, Curzio Cipriani, Gabriele Giuli, and William D. Birch for the type locality in the Santa Barbara mining district, Valdarno, Tuscany, Italy. It also honors St. Barbara (4th century, Nicomedia (now Jzmid, Turkey)), the patron saint of miners.
Consists of X-ray amorphous replacements of vivianite as well as smooth botryoidal crusts.
Unique Identifiers
Mindat ID:
11436
Long-form identifier:
mindat:1:1:11436:3
IMA Classification of Santabarbaraite
Approved
IMA Formula:
Fe3+3(PO4)2(OH)3·5H2O
Approval year:
2000
First published:
2003
Classification of Santabarbaraite
8.CE.80
8 : PHOSPHATES, ARSENATES, VANADATES
C : Phosphates without additional anions, with H2O
E : With only medium-sized cations, RO4:H2O about 1:2.5
8 : PHOSPHATES, ARSENATES, VANADATES
C : Phosphates without additional anions, with H2O
E : With only medium-sized cations, RO4:H2O about 1:2.5
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
Please only use the official IMA–CNMNC symbol. Older variants are listed for historical use only.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Sbb | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
| Sbb | The Canadian Mineralogist (2019) | The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). download |
Physical Properties of Santabarbaraite
Sub-Vitreous, Resinous, Waxy, Greasy
Transparency:
Transparent, Translucent
Colour:
Orange, orange brown, yellowish-brown
Streak:
Yellow to yellowish-brown
Tenacity:
Brittle
Cleavage:
None Observed
Parting:
parting according to the vivianite cleavage
Fracture:
Conchoidal
Density:
2.42 g/cm3 (Measured)
Optical Data of Santabarbaraite
Type:
Isotropic
RI values:
n = 1.695
Birefringence:
0.000
Surface Relief:
Very High (positive)
Relative to Canada balsam mounting medium (n ≈ 1.537).
Relative to Canada balsam mounting medium (n ≈ 1.537).
This shows the grain boundary and Becke line effect under plane-polarised
light, based on the contrast between this mineral's average refractive
index and the mounting medium. It does not take into account mineral
colouration.
In focus
Chemistry of Santabarbaraite
Mindat Formula:
Fe3+3(PO4)2(OH)3 · 5H2O
Element Weights:
Elements listed:
Crystallography of Santabarbaraite
Crystal System:
Amorphous
Morphology:
Pseudomorphs of vivianite or botryoidal crusts.
Comment:
X-ray amorphous; Partial replacements said to contain poorly crystalline vivianite, but the analogy to the phosphate analog of parasymplesite are unsupported by data.
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| - Å | () |
Comments:
Amorphous to X-rays.
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 7: Great Oxidation Event | <2.4 |
| 47a : [Near-surface hydration of prior minerals] | |
| 47c : [Carbonates, phosphates, borates, nitrates] |
Type Occurrence of Santabarbaraite
General Appearance of Type Material:
Resinous botryoidal masses and waxy to resinous replacements of vivianite.
Place of Conservation of Type Material:
Museum Victoria, Australia, catalogue numbers M22892
and M34637.
and M34637.
Geological Setting of Type Material:
In clays, pseudomorphous after vivianite
Associated Minerals at Type Locality:
Synonyms of Santabarbaraite
Other Language Names for Santabarbaraite
Dutch:Santabarbaraiet
German:Santabarbarait
Simplified Chinese:羟水磷铁石
Spanish:Santabarbaraita
Traditional Chinese:羥水磷鐵石
Kerchenskoe deposit, Kerchenskyi iron ore basin, Kerch Peninsula, Crimea, Ukraine