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Earlandite
A valid IMA mineral species - grandfathered
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About Earlandite
Arthur Earland
Formula:
Ca3[CH2(COO)-CHOH(COO)-CH2(COO)]2 · 4H2O
Colour:
White, pale yellow
Specific Gravity:
1.80 - 1.95
Crystal System:
Monoclinic
Name:
Named in honor of Arthur Earland (3 November 1866, Lewisham, London, England, UK - 27 March 1958), British oceanographer and foraminifera specialist. He studied sediments from the Weddell Sea near Antarctica returned by the ship Scotia, and identified grains of the new mineral.
Type Locality:
Chemically identical to calcium citrate tetrahydrate - a citric acid salt.
Occurs in unconsolidated ocean floor sediment at 2,580 meters in depth.
Occurs in unconsolidated ocean floor sediment at 2,580 meters in depth.
Unique Identifiers
Mindat ID:
1344
Long-form identifier:
mindat:1:1:1344:0
IMA Classification of Earlandite
Approved, 'Grandfathered' (first described prior to 1959)
IMA Formula:
Ca3(C6H5O7)3-2·4H2O
First published:
1936
Classification of Earlandite
10.AC.10
10 : ORGANIC COMPOUNDS
A : Salts of organic acids
C : Benzine Salts
10 : ORGANIC COMPOUNDS
A : Salts of organic acids
C : Benzine Salts
50.2.2.1
50 : ORGANIC COMPOUNDS
2 : Mellitates, Citrates, Cyanates, Acetates and Formates
50 : ORGANIC COMPOUNDS
2 : Mellitates, Citrates, Cyanates, Acetates and Formates
31.2.1
31 : Oxalates, Citrates, Mellitates and Acetates
2 : Citrates
31 : Oxalates, Citrates, Mellitates and Acetates
2 : Citrates
Mineral Symbols
As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Ear | IMA–CNMNC | Warr, L.N. (2021). IMA–CNMNC approved mineral symbols. Mineralogical Magazine, 85(3), 291-320. doi:10.1180/mgm.2021.43 |
Physical Properties of Earlandite
Transparency:
Translucent
Colour:
White, pale yellow
Comment:
Hardness not determined.
Density:
1.80 - 1.95 g/cm3 (Measured) 1.96 g/cm3 (Calculated)
Optical Data of Earlandite
Type:
Biaxial (+)
RI values:
nα = 1.515 nβ = 1.530 nγ = 1.580
2V:
Measured: 60° , Calculated: 50°
Max. Birefringence:
δ = 0.065
Based on recorded range of RI values above.
Based on recorded range of RI values above.
Interference Colours:
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
The colours simulate birefringence patterns seen in thin section under crossed polars. They do not take into account mineral colouration or opacity.
Michel-Levy Bar The default colours simulate the birefringence range for a 30 µm thin-section thickness. Adjust the slider to simulate a different thickness.
Grain Simulation You can rotate the grain simulation to show how this range might look as you rotated a sample under crossed polars. Each grain retains its interference colour (retardation) while its brightness falls to black at extinction and reaches a maximum between extinction positions.
Surface Relief:
None to Very Low
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
Interference Figure:
This shows the idealized biaxial acute bisectrix (Bxa) interference figure
- the conoscopic view for a grain cut perpendicular to the acute bisectrix, using
this mineral's 2V. The two small white dots mark the melatopes - the points
where the two optic axes emerge - and are shown only when they fall within the
field of view. The coloured bands are isochromatics, and the dark bands are
isogyres.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Rotate the stage: at 0°/90° the isogyres form a cross through the melatopes; at 45° they pull apart into curved hyperbolas. That splitting on rotation - absent in a uniaxial figure - is the standard diagnostic test for telling biaxial minerals from uniaxial ones. If 2V is large, the melatopes may fall outside the field of view, as they often do at the microscope too.
Dispersion:
r > v
Chemistry of Earlandite
Mindat Formula:
Ca3[CH2(COO)-CHOH(COO)-CH2(COO)]2 · 4H2O
Element Weights:
Elements listed:
Crystallography of Earlandite
Crystal System:
Monoclinic
Cell Parameters:
a = 30.94 Å, b = 5.93 Å, c = 10.56 Å
β = 93.74°
β = 93.74°
Ratio:
a:b:c = 5.218 : 1 : 1.781
Unit Cell V:
1,933.36 ų (Calculated from Unit Cell)
Z:
4
Morphology:
Veruginous, fine-grained nodules.
Comment:
Crystal System determination based on observations on synthetic material. Class and Space Group not determined.
Crystal Structure
Load
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Unit Cell | Unit Cell Packed
2x2x2 | 3x3x3 | 4x4x4
Show
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Big Balls | Small Balls | Just Balls | Spacefill
Polyhedra Off | Si Polyhedra | All Polyhedra
Remove metal-metal sticks
Display Options
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
Black Background | White Background
Perspective On | Perspective Off
2D | Stereo | Red-Blue | Red-Cyan
View
CIF File Best | x | y | z | a | b | c
CIF File Best | x | y | z | a | b | c
Rotation
Stop | Start
Stop | Start
Labels
Console Off | On | Grey | Yellow
Console Off | On | Grey | Yellow
Data courtesy of the American Mineralogist Crystal Structure Database. Click on an AMCSD ID to view structure
| ID | Species | Reference | Link | Year | Locality | Pressure (GPa) | Temp (K) |
|---|---|---|---|---|---|---|---|
| 0019542 | Earlandite | Herdtweck E, Kornprobst T, Sieber R, Straver L, Plank J (2011) Crystal structure, synthesis, and properties of tri-calcium di-citrate tetra-hydrate [Ca3(C6H5O7)2(H2O)2]*2H2O Zeitschrift fur Anorganische und Allgemeine Chemie 637 655-659 | 2011 | synthetic | 0 | 293 |
CIF Raw Data - click here to close
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 15.5 Å | (100) |
| 8.5 Å | (4) |
| 7.7 Å | (50) |
| 6.4 Å | (4) |
| 5.2 Å | (35) |
| 3.09 Å | (6) |
| 4.74 Å | (4) |
Geological Environment
Paragenetic Mode(s):
| Paragenetic Mode | Earliest Age (Ga) |
|---|---|
| Stage 3b: Earth’s earliest hydrosphere | >4.45 |
| 17 : Marine authigenic Hadean minerals (see also #24) | |
| Stage 10a: Neoproterozoic oxygenation/terrestrial biosphere | <0.6 |
| 49 : Oxic cellular biomineralization (see also #44) | <0.54 |
Type Occurrence of Earlandite
General Appearance of Type Material:
Warty,fine-grained nodules.
Place of Conservation of Type Material:
The Natural History Museum, London, England: #1936,978, 1936,979. Harvard University, Cambridge, Massachusetts, USA: #134573.U.S. National Museum of Natural History, Washington, D.C., USA: #105859, 162618.
Geological Setting of Type Material:
Unconsolidated ocean sediments.
Associated Minerals at Type Locality:
Other Language Names for Earlandite
Related Minerals - Strunz-mindat Grouping
Other Information
Health Risks:
No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care.
Internet Links for Earlandite
mindat.org URL:
https://www.mindat.org/min-1344.html
Please feel free to link to this page.
Please feel free to link to this page.
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External Links:
Mineral Dealers:
References for Earlandite
Reference List:
Bannister, F.A., Hey, M.H. (1936) Report on some crystalline components of the Weddell Sea deposits. Discovery Reports, 13. 60-69
Localities for Earlandite
Showing 1 localities.
symbol to view information about a locality.
The Locality List
- This locality has map coordinates listed.
- This locality has estimated coordinates.
ⓘ - Click for references and further information on this occurrence.
? - Indicates mineral may be doubtful at this locality.
- Good crystals or important locality for species.
- World class for species or very significant.
(TL) - Type Locality for a valid mineral species.
(FRL) - First Recorded Locality for everything else (eg varieties).
All localities listed without proper references should be considered as questionable.
Antarctica (TL) | |
| Palache et al. (1951) |
Quick NavTopAbout EarlanditeUnique IdentifiersIMA Classification Classification Mineral SymbolsPhysical Properties Optical Data Chemistry Crystallography Crystal StructureX-Ray Powder DiffractionGeological EnvironmentType Occurrence Other LanguagesStrunz-MindatOther InformationInternet Links References Localities Locality List
71°22'S; 16°34'W, Weddell Sea, West Antarctica, Antarctica