Loomisite (original) (raw)

A valid IMA mineral species

About LoomisiteHide

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Formula:

Ba[Be2P2O8] · H2O

Crystal System:

Monoclinic

Name:

Named after Tom Loomis, mineral collector and dealer from South Dakota, USA, who collected the type material.

Chemically related to minjiangite that may be treated as its anhydrous counterpart. Both are beryllophosphates.

Loomisite is the first natural example with the zeolite ABW-type framework, which is adopted by over 100 synthetic compounds with different chemical compositions.

Unique IdentifiersHide

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Long-form identifier:

mindat:1:1:56033:1

b7743157-d8e3-4f48-aa80-bf411c0e16c7

IMA Classification of LoomisiteHide

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IMA Formula:

Ba[Be2P2O8] · H2O

Type description reference:

Yang, Hexiong, Gu, Xiangping, Gibbs, Ronald B., Downs, Robert T. (2023) Loomisite, Ba[Be2P2O8]⋅H2O, the first natural example with the zeolite ABW-type framework, from Keystone, Pennington County, South Dakota, USA. Mineralogical Magazine, 87 (1) 79-85 doi:10.1180/mgm.2022.117

Classification of LoomisiteHide

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8.DN.

8 : PHOSPHATES, ARSENATES, VANADATES
D : Phosphates, etc. with additional anions, with H2O
N : With only large cations

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.

Physical Properties of LoomisiteHide

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Cleavage:

Perfect
{100} and {110}.

Density:

3.46(5) g/cm3 (Measured) 3.512 g/cm3 (Calculated)

Optical Data of LoomisiteHide

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RI values:

_n_α = 1.579(5) _n_β = 1.591(5) _n_γ = 1.606(5)

2V:

Measured: 82° (2), Calculated: 85°

δ = 0.027

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

Dispersion:

very weak with r > v

Pleochroism:

Non-pleochroic

Chemistry of LoomisiteHide

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Mindat Formula:

Ba[Be2P2O8] · H2O

Crystallography of LoomisiteHide

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Crystal System:

Monoclinic

Cell Parameters:

a = 7.629(2) Å, b = 9.429(2) Å, c = 4.762(1) Å
β = 91.272(5)°

Ratio:

a:b:c = 0.809 : 1 : 0.505

Unit Cell V:

342.46 ų (Calculated from Unit Cell)

Morphology:

Divergent sprays of very thin bladed crystals with a tapered termination.

Twinning:

Pervasively twinned on (100) with the twin law [1 0 0 / 0 -1 0 / 0 0 -1] or consist of multi-crystal intergrowth.

X-Ray Powder DiffractionHide

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Powder Diffraction Data:

Type Occurrence of LoomisiteHide

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General Appearance of Type Material:

Divergent sprays of very thin bladed crystals that gently taper to a blunt termination. Individual crystals are found up to 0.80 x 0.06 x 0.03 mm.

Place of Conservation of Type Material:

Type material is deposited in the collections of the University of Arizona Alfie Norville Gem and Mineral Museum, 15 N Church Ave, Tucson, AZ 85701, USA, catalogue no. 22710 (holotype), and the RRUFF Project, deposition no. R210017 (cotype).

Geological Setting of Type Material:

Associated Minerals at Type Locality:

Synonyms of LoomisiteHide

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Relationship of Loomisite to other SpeciesHide

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Other Members of this group:

Related Minerals - Strunz-mindat GroupingHide

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Other InformationHide

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Notes:

Insoluble in water or HCl.

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 LoomisiteHide

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References for LoomisiteHide

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Reference List:

Yang, Hexiong, Gu, Xiangping, Gibbs, Ronald B., Downs, Robert T. (2023) Loomisite, Ba[Be2P2O8]⋅H2O, the first natural example with the zeolite ABW-type framework, from Keystone, Pennington County, South Dakota, USA. Mineralogical Magazine, 87 (1) 79-85 doi:10.1180/mgm.2022.117

Localities for LoomisiteHide

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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.