Cabrerite
A valid IMA mineral species
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About Cabrerite
Formula:
NiMg2(AsO4)2 · 8H2O
Colour:
Green, pale greenish, pale pinkish
Lustre:
Vitreous
Hardness:
2½
Specific Gravity:
2.93
Crystal System:
Monoclinic
Member of:
Name:
Dana (1868) used the name "cabrerite" for a Ni-Co-Mg-arsenate mineral from Sierra Cabrera, Almería, Andalusia, Spain, which was described by Ferber (1863) as Wasserhaltige Nickeloxyd Magnesia. Giuseppetti and Tadini (1982) published a crystal structure refinement for a crystal from Lavrion, Greece that they refer to as cabrerite and for which they report the empirical formula (Ni2.2Mg0.7Fe0.1)(AsO4)2·8H2O. Their structure study shows Mg to be almost entirely ordered into the M2 site (M1: Ni0.976Mg0.024; M2: Ni0.696Mg0.304); however, Ni was still dominant in both sites.
Cation-ordered intermediate phase between annabergite and hörnesite, with Ni dominant at M1, Mg dominant at M2, and T = As.
Unique combination of elements (at the upload time).
The structure consists of NiO2(H2O)4 octahedra and Mg2O6(H2O)4 edge-sharing octahedral dimers that are linked together via AsO4 tetrahedra and hydrogen bonds to form layers parallel to {010}.
Not to be confused with Cabrerite (of Dana), a historic name for a Mg-bearing variety of annabergite.
The Ni analogue of gritsenkoite.
Unique combination of elements (at the upload time).
The structure consists of NiO2(H2O)4 octahedra and Mg2O6(H2O)4 edge-sharing octahedral dimers that are linked together via AsO4 tetrahedra and hydrogen bonds to form layers parallel to {010}.
Not to be confused with Cabrerite (of Dana), a historic name for a Mg-bearing variety of annabergite.
The Ni analogue of gritsenkoite.
Unique Identifiers
Mindat ID:
471114
Long-form identifier:
mindat:1:1:471114:4
Similar Names
| Cabrerite (of Dana) | A synonym of 'Magnesium-bearing Annabergite' |
IMA Classification of Cabrerite
Approved
IMA Formula:
Ni2+Mg2(As5+O4)2·8H2O
Approval year:
2024
Classification of Cabrerite
8.CE.40
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.
| Symbol | Source | Reference for Standard |
|---|---|---|
| Cabr | 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 Cabrerite
Vitreous
Transparency:
Transparent
Colour:
Green, pale greenish, pale pinkish
Streak:
Pale green to white
Hardness:
2½ on Mohs scale
Tenacity:
Sectile
Cleavage:
Perfect
three cleavages: perfect on {010}, fair on {100} and poor on {102}.
three cleavages: perfect on {010}, fair on {100} and poor on {102}.
Fracture:
Irregular/Uneven, Step-Like
Density:
2.93(2) g/cm3 (Measured) 2.915 g/cm3 (Calculated)
Optical Data of Cabrerite
Type:
Biaxial (+)
RI values:
nα = 1.609(2) nβ = 1.633(2) nγ = 1.667(2)
2V:
Measured: 82° (2)
Max. Birefringence:
δ = 0.058
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:
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
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:
slight r < v dispersion
Orientation:
X = b, Z ^ c = 37° in obtuse β
Pleochroism:
Non-pleochroic
Chemistry of Cabrerite
Mindat Formula:
NiMg2(AsO4)2 · 8H2O
Element Weights:
Crystallography of Cabrerite
Crystal System:
Monoclinic
Class (H-M):
2/m - Prismatic
Space Group:
B2/m
Setting:
C2/m
Cell Parameters:
a = 10.205(1) Å, b = 13.377(1) Å, c = 4.7382(4) Å
β = 105.057(7)°
β = 105.057(7)°
Ratio:
a:b:c = 0.763 : 1 : 0.354
Unit Cell V:
624.62 ų (Calculated from Unit Cell)
Z:
2
Twinning:
None
X-Ray Powder Diffraction
Powder Diffraction Data:
| d-spacing | Intensity |
|---|---|
| 7.920 Å | (34) |
| 6.666 Å | (100) |
| 4.369 Å | (65) |
| 3.302 Å | (84) |
| 2.987 Å | (88) |
| 2.722 Å | (74) |
| 2.314 Å | (44) |
| 1.651 Å | (44) |
Type Occurrence of Cabrerite
General Appearance of Type Material:
divergent groups of green blades up to 1 mm long. Blades are elongated and striated parallel to [001],
Place of Conservation of Type Material:
Type material is deposited in the collections of the Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, CA 90007, USA, catalogue number 65733
Geological Setting of Type Material:
Oxygenated Ni Co arsenides
Associated Minerals at Type Locality:
Synonyms of Cabrerite
Other Language Names for Cabrerite
Relationship of Cabrerite to other Species
Member of:
Other Members of Vivianite Group:
| Annabergite | Ni3(AsO4)2 · 8H2O | Mon. 2/m : B2/m |
| Arupite | Ni3(PO4)2 · 8H2O | Mon. 2/m : B2/m |
| Babánekite | Cu3(AsO4)2 · 8H2O | Mon. 2/m : B2/m |
| Barićite | (Mg,Fe)3(PO4)2 · 8H2O | Mon. 2/m : B2/m |
| Erythrite | Co3(AsO4)2 · 8H2O | Mon. 2/m : B2/m |
| Gritsenkoite | CoMg2(AsO4)2(H2O)8 | Mon. 2/m : B2/m |
| Hörnesite | Mg3(AsO4)2 · 8H2O | Mon. 2/m : B2/m |
| Köttigite | Zn3(AsO4)2 · 8H2O | Mon. 2/m : B2/m |
| Manganohörnesite | Mn2+3(AsO4)2 · 8H2O | Mon. 2/m : P2/m |
| Monteneroite | Cu2+Mn2+2(AsO4)2 · 8H2O | Mon. 2/m : B2/m |
| Pakhomovskyite | Co3(PO4)2 · 8H2O | Mon. 2/m : B2/m |
| Parasymplesite | Fe2+3(AsO4)2 · 8H2O | Mon. 2/m : B2/m |
| Vivianite | Fe2+Fe2+2(PO4)2 · 8H2O | Mon. 2/m : B2/m |
| Zincocabrerite | ZnMg2(AsO4)2(H2O)8 | Mon. 2/m : B2/m |
Related Minerals - Strunz-mindat Grouping
| 8.CE. | Monteneroite | Cu2+Mn2+2(AsO4)2 · 8H2O |
| 8.CE. | Belmonteite | CaMn2(AsO4)2 · 7H2O |
| 8.CE.X | Babánekite | Cu3(AsO4)2 · 8H2O |
| 8.CE.05 | Chudobaite | Mg5(AsO4)2(AsO3OH)2 · 10H2O |
| 8.CE.05 | Geigerite | Mn2+5(AsO4)2(HAsO4)2 · 10H2O |
| 8.CE.10 | Newberyite | Mg(PO3OH) · 3H2O |
| 8.CE.10 | Manganonewberyite | Mn(PO3OH)(H2O)3 |
| 8.CE.15 | Fanguangite | (MoO2)(PO3OH) · 4H2O |
| 8.CE.15 | Brassite | Mg(HAsO4) · 4H2O |
| 8.CE.20 | Phosphorrösslerite | Mg(PO3OH) · 7H2O |
| 8.CE.20 | Rösslerite | Mg(HAsO4) · 7H2O |
| 8.CE.25 | Switzerite | Mn2+3(PO4)2 · 7H2O |
| 8.CE.25 | Metaswitzerite | Mn2+3(PO4)2 · 4H2O |
| 8.CE.30 | Pradetite | CoCu4(AsO4)2(HAsO4)2 · 9H2O |
| 8.CE.30 | Veselovskýite | ZnCu4(AsO4)2(HAsO4)2 · 9H2O |
| 8.CE.30 | Lindackerite | CuCu4(AsO4)2(HAsO4)2 · 9H2O |
| 8.CE.30 | Klajite | MnCu4(AsO4)2(HAsO4)2 · 9-10H2O |
| 8.CE.30 | Hloušekite | (Ni,Co)Cu4(AsO4)2(AsO3OH)2 · 9H2O |
| 8.CE.30 | Ondrušite | CaCu4(AsO4)2(HAsO4)2 · 10H2O |
| 8.CE.35 | Bobierrite | Mg3(PO4)2 · 8H2O |
| 8.CE.40 | Barićite | (Mg,Fe)3(PO4)2 · 8H2O |
| 8.CE.40 | Parasymplesite | Fe2+3(AsO4)2 · 8H2O |
| 8.CE.40 | Gritsenkoite | CoMg2(AsO4)2(H2O)8 |
| 8.CE.40 | Pakhomovskyite | Co3(PO4)2 · 8H2O |
| 8.CE.40 | Vivianite | Fe2+Fe2+2(PO4)2 · 8H2O |
| 8.CE.40 | Arupite | Ni3(PO4)2 · 8H2O |
| 8.CE.40 | Erythrite | Co3(AsO4)2 · 8H2O |
| 8.CE.40 | Hörnesite | Mg3(AsO4)2 · 8H2O |
| 8.CE.40 | Manganohörnesite | Mn2+3(AsO4)2 · 8H2O |
| 8.CE.40 | Köttigite | Zn3(AsO4)2 · 8H2O |
| 8.CE.40 | Ferrisymplesite | Fe3+3(AsO4)2(OH)3 · 5H2O |
| 8.CE.40 | Annabergite | Ni3(AsO4)2 · 8H2O |
| 8.CE.45 | Symplesite | Fe2+3(AsO4)2 · 8H2O |
| 8.CE.50 | Cattiite | Mg3(PO4)2 · 22H2O |
| 8.CE.55 | Koninckite | Fe3+PO4 · 3H2O |
| 8.CE.60 | Kaňkite | FeAsO4 · 3.5H2O |
| 8.CE.60 | Hilarionite | Fe3+2(SO4)(AsO4)(OH) · 6H2O |
| 8.CE.65 | Steigerite | Al(VO4) · 3H2O |
| 8.CE.70 | Metaschoderite | Al2(PO4)(VO4) · 6H2O |
| 8.CE.70 | Schoderite | Al2(PO4)(VO4) · 8H2O |
| 8.CE.75 | Zigrasite | MgZr(PO4)2 · 4H2O |
| 8.CE.75 | 'UM2009-11-PO:CaHZr' | CaZr[PO4]2 · 4H2O |
| 8.CE.75 | Malhmoodite | FeZr(PO4)2 · 4H2O |
| 8.CE.80 | Santabarbaraite | Fe3+3(PO4)2(OH)3 · 5H2O |
| 8.CE.85 | Metaköttigite | (Zn,Fe,Fe)3(AsO4)2 · 8(H2O,OH) |
| 8.CE.90 | Slavkovite | Cu13(AsO4)6(AsO3OH)4 · 23H2O |
Fluorescence of Cabrerite
none
Other Information
Notes:
The mineral dissolves slowly in dilute HCl at room temperature.
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 Cabrerite
mindat.org URL:
https://www.mindat.org/min-471114.html
Please feel free to link to this page.
Please feel free to link to this page.
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References for Cabrerite
Reference List:
Wildner, Manfred, Giester, Gerald, Lengauer, Christian L., Mccammon, Catherine A. (1996) Structure and crystal chemistry of vivianite-type compounds: Crystal structures of erythrite and annabergite with a Mössbauer study of erythrite. European Journal of Mineralogy, 8 (1) 187-192 doi:10.1127/ejm/8/1/0187
Rojo, J.M.; Mesa, J.L.; Pizarro, J.L.; Lezama, L.; Arriortua, M.I.; Rojo, T. (1996) Spectroscopic and magnetic study of the (Mg,M)3(AsO4)2·8H2O (M = Ni2+, Co2+) arsenates. Materials Research Bulletin, 31 (8). 925-934 doi:10.1016/s0025-5408(96)00088-8
Localities for Cabrerite
Showing 5 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.
Germany | |
| Gerhard Möhn Collection |
Italy | |
| //doi.org/10.57635/MICRO.2025.23.17 |
Switzerland | |
| Ansermet et al. (2025) |
USA | |
| Tony Kampf (XEDS; 2025) |
| Kampf et al. (2024) +1 other reference |
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Lovelock Mine, Bolivia, Cottonwood Canyon, Churchill County, Nevada, USA