Meyerhofferite (original) (raw)

A valid IMA mineral species - grandfathered

About MeyerhofferiteHide

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Formula:

CaB3O3(OH)5 · H2O

formerly given as Ca2(H3B3O7)2.4H2O

Name:

Named in honor of Wilhelm Meyerhoffer (13 September 1864, Pinsk, Belarus – 21 April 1906, Merano, Italy), chemist at the University of Vienna and University of Berlin. He was a collaborator with J.H. van't Hoff on the composition and origin of saline minerals, and he synthesized the compound.

Inderite Group.
Occurs principally as an alteration product of Inyoite.

The crystal structure is based on:
* two BO2(OH)2 tetrahedra,
* one BO2(OH) triangular group; these two are linked via corner-sharing to give [B3O3(OH)5]2− rings;
* distorted Ca polyhedra, CaO3(OH)4(OH2), linked via edge-sharing to give infinite chains || [001];
* H bonding system connecting chains comprising the Ca polyhedra and B-bearing rings.

Unique IdentifiersHide

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Long-form identifier:

mindat:1:1:2699:0

16e72009-5e46-4a1a-9ce6-b91da4322978

IMA Classification of MeyerhofferiteHide

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Approved, 'Grandfathered' (first described prior to 1959)

Classification of MeyerhofferiteHide

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6.CA.30

6 : BORATES
C : Triborates
A : Neso-triborates

26.3.2.1

26 : HYDRATED BORATES CONTAINING HYDROXYL OR HALOGEN
3 : Triborates

9.3.17

9 : Borates
3 : Borates of Ca and Sr

Mineral SymbolsHide

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As of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams.

Pronunciation of MeyerhofferiteHide

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Pronunciation:

Physical Properties of MeyerhofferiteHide

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Transparency:

Transparent, Translucent

Cleavage:

Perfect
On {010} perfect; {100} and {110} in traces.

Density:

2.12 g/cm3 (Measured) 2.116 g/cm3 (Calculated)

Optical Data of MeyerhofferiteHide

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RI values:

_n_α = 1.500 _n_β = 1.535 _n_γ = 1.560

2V:

Measured: 78° , Calculated: 78°

δ = 0.060

Image shows birefringence interference colour range (at 30µm thickness)
and does not take into account mineral colouration.

Dispersion:

relatively weak

Optical Extinction:

X (165°,62°); Y (45°30′,47°); Z (-83°,55°) with c(0°,0°) and b∗(0°,90°) using (φ,ρ).

Chemistry of MeyerhofferiteHide

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Mindat Formula:

CaB3O3(OH)5 · H2O

formerly given as Ca2(H3B3O7)2.4H2O

Crystallography of MeyerhofferiteHide

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Class (H-M):

1 - Pinacoidal

Cell Parameters:

a = 6.632(1) Å, b = 8.337(1) Å, c = 6.4748(6) Å
α = 90.81(1)°, β = 101.97(1)°, γ = 86.76(1)°

Ratio:

a:b:c = 0.795 : 1 : 0.777

Unit Cell V:

349.65 ų (Calculated from Unit Cell)

Morphology:

Crystals elongated [001] and usually flattened (100). Fibrous. As pseudomorphs after inyoite.

Forms include:
Pinacoids: a{100}, b{010}, c{001}
Positive prisms: k{370}, l{120}, A{350}, j{450}, m{110}, q{210}, n{520}, s{310}, B{510}, r{810}.
Negative prisms: v{350}, M{110}, w{430}, h{310}.
Positive domes: t{101}, d{12.0.11}, e{706}, f{605}, g{504}, i{705}, x{302}, z{12.0.1}.
Negative dome: y{101}.
Pyramid: p{111}.

Twinning:

No twinning observed.

Comment:

Cell parameters are from Burns and Hawthorne (1993).

Crystallographic forms of MeyerhofferiteHide

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Crystal Atlas:

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3d models and HTML5 code kindly provided bywww.smorf.nl.

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ID	Species	Reference	Link	Year	Locality	Pressure (GPa)	Temp (K)
0005296	Meyerhofferite	Burns P C, Hawthorne F C (1993) Hydrogen bonding in meyerhofferite: An X-ray and structure energy study from Mount Blanco, Death Valley, California The Canadian Mineralogist 31 305-312		1993	Mount Blanco, Death Valley, California, USA	0	293

CIF Raw Data - click here to close

X-Ray Powder DiffractionHide

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Powder Diffraction Data:

Comments:

Mt. Blanco, California, USA. ICDD 12-411.

Geological EnvironmentHide

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Type Occurrence of MeyerhofferiteHide

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General Appearance of Type Material:

Reticulated structures of white silky fibrous material. The crystals are prismatic and up to about 1 mm thick and 10 mm long.

Place of Conservation of Type Material:

Harvard Mineralogical Museum, Cambridge, Massachusetts, USA, number 134572 (type).
National Museum of Natural History, Washington, D.C., USA, numbers 087237 and 093640 (type).

Geological Setting of Type Material:

A secondary borate mineral, formed as an alteration of inyoite.

Associated Minerals at Type Locality:

Other Language Names for MeyerhofferiteHide

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Relationship of Meyerhofferite to other SpeciesHide

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Other Members of this group:

Common AssociatesHide

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Associated Minerals Based on Photo Data:

Related Minerals - Strunz-mindat GroupingHide

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Other InformationHide

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Thermal Behaviour:

Heated in a blowpipe flame it fuses readily without decrepitation but with intumescence to an opaque white enamel, giving a greenish color to the flame. Heated in a closed tube, it fuses, giving off abundant water.

Notes:

Readily soluble in acids.

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 MeyerhofferiteHide

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References for MeyerhofferiteHide

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Reference List:

**Palache, Charles, Berman, Harry, Frondel, Clifford (1951) The System of Mineralogy (7th ed.) Vol. 2 - Halides, Nitrates, Borates, Carbonates, Sulfates, Phosphates, Arsenates, Tungstates, Molybdates, Ect. John Wiley and Sons, New York.**pp.356-358

Frost, Ray L., López, Andrés, Xi, Yunfei, Scholz, Ricardo, Costa, Geraldo Magela da, Belotti, Fernanda M., Lima, Rosa Malena Fernandes (2013) Vibrational spectroscopy of the mineral meyerhofferite CaB3O3(OH)5·H2O – An assessment of the molecular structure. Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 114. 27-32 doi:10.1016/j.saa.2013.05.016

Gatta, G. Diego, Guastella, Giorgio, Capelli, Silvia C., Comboni, Davide, Guastoni, Alessandro (2022) On the crystal-chemistry of meyerhofferite, CaB3O3(OH)5·H2O. Physics and Chemistry of Minerals, 49 (7) doi:10.1007/s00269-022-01199-1

Localities for MeyerhofferiteHide

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This map shows a selection of localities that have latitude and longitude coordinates recorded. Click on the symbol to view information about a locality. The symbol next to localities in the list can be used to jump to that position on the map.

Locality ListHide

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- 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). Struck out - Mineral was erroneously reported from this locality. Faded * - Never found at this locality but inferred to have existed at some point in the past (e.g. from pseudomorphs).

All localities listed without proper references should be considered as questionable.