Classification of Olmiite |
| IMA status: | Approved 2006 |
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| Strunz 8th edition ID: | 8/B.22-22
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| Nickel-Strunz 10th (pending) edition ID: | 9.AF.90
9 : SILICATES (Germanates) A : Nesosilicates F : Nesosilicates with additional anions; cations in [4], [5] and/or only [6] coordination |
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| mindat.org URL: | http://www.mindat.org/min-30762.html Please feel free to link to this page. |
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Type Occurrence of Olmiite |
| Type Locality: | N'Chwaning II Mine, N'Chwaning Mines, Kuruman, Kalahari manganese fields, Northern Cape Province, South Africa |
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| General Appearance of Type Material: | Wheat sheaf aggregates. |
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| Year of Discovery: | 2006 |
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| Associated Minerals at type locality: | |
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Physical Properties of Olmiite |
| Lustre: | Vitreous |
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| Diaphaneity (Transparency): | Transparent |
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| Colour: | Pale to intense reddish pink. |
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| Streak: | White |
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| Hardness (Mohs): | 5 - 5½ |
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| Tenacity: | Brittle |
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| Cleavage: | None Observed |
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| Fracture: | Irregular/Uneven |
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| Density (measured): | 3.05 g/cm3 |
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| Density (calculated): | 3.102 g/cm3 |
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| Comment: | Calculated value based on unit cell volume; a value of 3.109 from powder data. |
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Crystallography of Olmiite |
| Crystal System: | Orthorhombic |
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| Class (H-M): | mmm (2/m 2/m 2/m) - Dipyramidal |
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| Space Group: | Pbca {P21/b 21/c 21/a} |
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| Cell Parameters: | a = 9.249Å, b = 9.076Å, c = 10.342Å
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| Ratio: | a:b:c = 1.019 : 1 : 1.139 |
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| Unit Cell Volume: | V 868 ų |
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| Z: | 8 |
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| Morphology: | Crystals minute. Aggregates resemble wheat sheaves. |
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| X-Ray Powder Diffraction: | | d-spacing | | Intensity | | 4.14 | | (60) | | 4.10 | | (30) | | 3.19 | | (100) | | 2.807 | | (35) | | 2.762 | | (30) | | 2.545 | | (35) | | 2.521 | | (30) | | 2.361 | | (40) |
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Optical Data of Olmiite |
| Type: | Biaxial (+) |
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| RI values: | nα = 1.663(1) nβ = 1.672(1) nγ = 1.694(1) |
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| 2V: | Measured: 71° , Calculated: 66° |
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| Maximum Birefringence: | δ = 0.031
 Chart shows birefringence interference colour range (at 30µm thickness) and does not take into account mineral colouration. |
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| Surface Relief: | High |
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| Dispersion: | r > v distinct |
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| Pleochroism: | Non-pleochroic |
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Chemical Properties of Olmiite |
| Formula: | |
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| Essential elements: | Ca, H, Mn, O, Si |
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| All elements listed in formula: | Ca, H, Mn, O, Si |
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Relationship of Olmiite to other Species |
| Series: | Forms a series with Poldervaartite (see here) |
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Related Minerals - Nickel-Strunz Grouping):
- + | |
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Other Names for Olmiite |
| Synonyms: | |
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| Other Languages: | |
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Other Information |
| Fluorescence in UV light: | Deep red (SW UV) |
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| Health Warning: | No information on health risks for this material has been entered into the database. You should always treat mineral specimens with care. |
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References for Olmiite |
Reference List:
- + | Bonazzi, P., Bindi, L., Medenbach, O., Pagano, R., Lampronti, Menchetti, S. (2007): Olmiite, CaMn[SiO3(OH)](OH), the Mn-dominant analogue of poldervaartite, a new mineral species from Kalahari manganese fields (Republic of South Africa), Mineralogical Magazine, 71, 193-291. |
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Internet Links for Olmiite |
| Search Engines: |
Look for Olmiite on Google
Look for Olmiite images on Google |
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| External Links: | Look for Olmiite on WebmineralLook for Olmiite on Athena MineralogyLook for Olmiite on Mineralien AtlasRaman and XRD data at RRUFF projectAmerican Mineralogist Crystal Structure Database |
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| Mineral Dealers: | Fabre Minerals - search for Olmiite specimensSearch for Olmiite from all mineral dealers at minfind.comSearch for - Olmiite - on e-Rocks Mineral Sales & AuctionsThe Arkenstone - Fine MineralsTop quality minerals from Kristalle of CaliforniaBuy from David K Joyce mineralsPricedownminerals.com - Reverse Auctions and ShopSearch for minerals at HeliodorBuy fine minerals and gemstones from Pala InternationalFine Minerals from Weinrich Minerals, Inc.Wilensky Fine MineralsVisit the Pueblo Gem and Mineral show, Tucson 2012 |
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| Specimens: | The following Olmiite specimens are currently listed for sale on minfind.com. |
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| Jobs: | Mining & Geology Jobs |
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Localities for Olmiite |
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