Liroconite
| Liroconite | |
|---|---|
 |
|
| General and classification | |
| other names |
|
| chemical formula | Cu 2 Al [(OH) 4 | AsO 4 ] • 4 H 2 O |
|
Mineral class (and possibly department) |
Phosphates, arsenates and vanadates |
|
System no. to Strunz and to Dana |
8.DF.20 ( 8th edition : VII / D.20) 02.02.01.01 |
| Similar minerals | Azurite , pseudomalachite |
| Crystallographic Data | |
| Crystal system | monoclinic |
| Crystal class ; symbol | monoclinic prismatic; 2 / m |
| Room group (no.) | I 2 / a (No. 15) |
| Lattice parameters |
a = 12.66 Å ; b = 7.56 Å; c = 9.91 Å β = 91.3 ° |
| Formula units | Z = 4 |
| Physical Properties | |
| Mohs hardness | 2 to 2.5 |
| Density (g / cm 3 ) | measured: 2.94 to 3.01; calculated: [3.03] |
| Cleavage | indistinct after {110} and {011} |
| Break ; Tenacity | shell-like to uneven |
| colour | blue to green |
| Line color | Light Blue |
| transparency | translucent to opaque |
| shine | Glass gloss, resin gloss |
| Crystal optics | |
| Refractive indices |
n α = 1.612 n β = 1.652 n γ = 1.675 |
| Birefringence | δ = 0.063 |
| Optical character | biaxial negative |
| Axis angle | 2V = measured: 67 °; calculated: 72 ° |
Lirokonit , as Chalcophacit or Chalcophasit or under his miner's name Linsenerz or lens copper known is a rarely occurring mineral from the mineral class of " phosphates , arsenates and vanadates ". It crystallizes in the monoclinic crystal system with the chemical composition Cu 2 Al [(OH) 4 | AsO 4 ] • 4 H 2 O and develops mostly transparent to translucent crystals with a lenticular or dipyramidal habit , but also granular to massive mineral aggregates and blue to green color with light blue stroke color .
Etymology and history
The mineral was named after its delicate light blue line after the Greek words λειρός for pale or light and κουία for powder or powder.
Lirokonite was first found in the "Wheal Gorland" mine near Gwennap in Cornwall (Great Britain) and first described in 1822 by Friedrich Mohs , who called the mineral Lirokon malachite . Wilhelm Ritter von Haidinger converted this designation into liroconite in 1825 when he translated Mohs' work Treatise on Mineralogy of the Natural History of the Mineral Kingdom .
classification
In the now outdated, but still in use 8th edition of the mineral classification according to Strunz , the liroconite belonged to the mineral class of "phosphates, arsenates and vanadates" and there to the department of "water-containing phosphates with foreign anions ", where it together with chalcophyllite , cerulite , leogangite , Parnauit and Zapatalit formed a separate group.
The 9th edition of Strunz's mineral systematics , which has been in effect since 2001 and is used by the International Mineralogical Association (IMA), also assigns liroconite to the class of "phosphates, arsenates and vanadates" and there to the department of "phosphates, etc. with additional anions ; with H 2 O “. However, this section is further subdivided according to the size of the cations involved and the molar ratio of the other anions to the phosphate, arsenate or vanadate complex, so that the mineral is classified in the sub-section “With only medium-sized cations; (OH etc.): RO 4 > 3: 1 “can be found where it is the only member of the unnamed group 8.DF.20 .
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns liroconite to the class of "phosphates, arsenates and vanadates" and there to the category of "anhydrous phosphates, etc., with hydroxyl or halogen". Here he is to be found as the only member of the unnamed group 42.02.01 within the subdivision of " Water-containing phosphates etc., with hydroxyl or halogen with (AB) 3 (XO 4 ) Z q × x (H 2 O) ".
Education and Locations
Lirokonit is a typical secondary mineral and formed in the oxidation zone of copper - deposits . Accompanying minerals include chalcophyllite , cornwallite , cuprite , clinoclase , malachite , olivite , strashimirite and limonite .
Overall, Lirokonite has so far (as of 2011) been found at around 20 sites. In addition to its Wheal Gorland type locality , the mineral was also found in the United Kingdom in the “Ting Tang Mine” near Carharrack “Wheal Unity” near Gwennap and in the “Engine Vein Mine” near Alderley Edge in the county of Cheshire , also in Cornwall. Providence Mines ”at Lelant , the“ Botallack Mine ”at St Just in Penwith and the“ Old Potts Gill Mine ”at Potts Gill in Cumberland .
In Germany, Lirokonit was found in the "Castor Mine" near Loope (North Rhine-Westphalia), the "Altväter including Eschig Mine" near Sayda (Saxony) and at Tännig near Bad Lobenstein and Ullersreuth (Thuringia).
Other locations are in Australia , Slovakia , Spain and the United States (USA).
Crystal structure
Liroconite crystallizes monoclinically in the space group I 2 / a (space group no. 15) with the lattice parameters a = 12.66 Å ; b = 7.56 Å; c = 9.91 Å and β = 91.3 ° and 4 formula units per unit cell .
See also
Individual evidence
- ↑ a b c d e Hugo Strunz , Ernest H. Nickel: Strunz Mineralogical Tables . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p. 506 .
- ↑ Webmineral - Liroconite (English)
- ↑ a b Handbook of Mineralogy - Liroconite (English, PDF 65 kB)
- ↑ a b c d e Liroconite at mindat.org (engl.)
- ↑ Frederick Mohs: Treatise on Mineralogy on the Natural History of the Mineral Kingdom , translated by William Haidinger, Edinburgh 1825 (PDF; 137 kB)
literature
- Petr Korbel, Milan Novák: Encyclopedia of Minerals . Nebel Verlag GmbH, Eggolsheim 2002, ISBN 3-89555-076-0 , p. 186 .
Web links
- Mineral Atlas: Liroconite (Wiki)