Diaboleite
| Diaboleite | |
|---|---|
 | |
| General | |
| Category | Halide mineral |
| Formula (repeating unit) | Pb2CuCl2(OH)4 |
| IMA symbol | Dbol[1] |
| Strunz classification | 3.DB.05 |
| Dana classification | 10.6.1.1 |
| Crystal system | Tetragonal |
| Crystal class | Ditetragonal pyramidal (4mm) H-M symbol: (4mm) |
| Space group | P4mm |
| Unit cell | a = 5.880, c = 5.500 Å, Z = 1[2] |
| Identification | |
| Color | Blue |
| Crystal habit | As square tabular crystals, thin plates, massive |
| Cleavage | Perfect on {001} |
| Fracture | Conchoidal |
| Tenacity | Brittle |
| Mohs scale hardness | 2.5 |
| Luster | Adamantine, pearly on cleavages[2] |
| Streak | Pale blue[2] |
| Diaphaneity | Transparent to translucent[2] |
| Density | 5.41 to 5.43 g/cm3 |
| Optical properties | Uniaxial (−) |
| Refractive index | nω = 1.980, nε = 1.850 |
| Birefringence | δ = 0.130 |
| Absorption spectra | O > E, in thick fragments[2] |
| Solubility | Completely soluble in nitric acid |
| References | [3] |
Diaboleite is a blue-colored mineral with formula Pb2CuCl2(OH)4. It was discovered in England in 1923 and named diaboleite, from the Greek word διά and boleite, meaning "distinct from boleite".[3] The mineral has since been found in a number of countries.
Description
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Diaboleite is deep blue in color and pale blue in transmitted light. The mineral occurs as tabular crystals up to 2 cm (0.8 in) in size, as subparallel aggregates, or it has massive habit. Vicinal forms of the tabular crystals have a square or octagonal outline and rarely exhibit pyramidal hemihedralism.[2]
Formation
[edit]Diaboleite occurs in manganese oxide ores, as a secondary mineral in lead and copper oxide ores, and in seawater-exposed slag. Diaboleite has been found in association with atacamite, boleite, caledonite, cerussite, chloroxiphite, hydrocerussite, leadhillite, mendipite, paratacamite, phosgenite, and wherryite.[2]
A study in 1986 synthesized diaboleite crystals up to 0.18 mm (0.0071 in) in size using two different methods. The study demonstrated that diaboleite is a low-temperature phase, that is stable under hydrothermal conditions at temperatures less than 100 to 170 °C (212 to 338 °F). At higher temperatures, the first stable mineral to form is cumengeite.[4]
History
[edit]In 1923, diaboleite was discovered at Higher Pitts Mine in the Mendip Hills of Somerset, England,[3] and described by L. J. Spencer and E.D. Mountain.[5] The study of the similar mineral boleite was perplexing at the time and this new mineral only compounded the difficulty. As insufficient material was available for a full investigation, Spencer and Mountain named it diaboleite, meaning "distinct from boleite", out of "desperation".[6]
The mineral was grandfathered as a valid mineral by the International Mineralogical Association as it was described prior to 1959.[3]
Distribution
[edit]As of 2012[update], diaboleite has been found in Australia, Austria, Chile, France, Germany, Greece, Iran, Italy, Russia, South Africa, the UK and the US.[2][3] The type material is held at the Natural History Museum in London and the National Museum of Natural History in Washington, D.C.[2]
References
[edit]- Citations
- ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
- ^ a b c d e f g h i "Diaboleite" (PDF). Handbook of Mineralogy. Retrieved June 11, 2012.
- ^ a b c d e "Diaboleite". Mindat. Retrieved June 11, 2012.
- ^ Winchell, p. 934.
- ^ Spencer, p. 78.
- ^ Spencer, p. 79.
- Bibliography
- Spencer, L. J.; Mountain, E. D. (September 1923). "Diaboleite" (PDF). Mineralogical Magazine. 20 (102). Mineralogical Society: 78–80. doi:10.1180/minmag.1923.020.102.01. Archived from the original (PDF) on 2016-03-04. Retrieved 2012-06-12.
- Winchell, R. E.; Wenden, H. E. (November 1968). "Synthesis and Study of Diaboleïte" (PDF). Mineralogical Magazine. 36 (283). Mineralogical Society: 933–939. Bibcode:1968MinM...36..933W. doi:10.1180/minmag.1968.283.036.03. Archived from the original (PDF) on 2014-05-14. Retrieved 2012-06-12.
Further reading
[edit]- Cooper, Mark A.; Hawthorne, Frank C. (October 1995). "Diaboleite, Pb2Cu(OH)4Cl2, a defect perovskite structure with stereoactive long-pair behavior of Pb (super 2+)". Canadian Mineralogist. 33 (5): 1125–1129. (subscription required)
- Palache, Charles (October 1941). "Diabloeite from Mammoth Mine, Tiger, Arizona" (PDF). American Mineralogist. 26 (10). Mineralogical Society of America: 605–612.
External links
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Media related to Diaboleite at Wikimedia Commons
