Yingjiangit
| Yingjiangit | |
|---|---|
.jpg) |
|
| General and classification | |
| other names |
IMA 1989-001 |
| chemical formula | K 2 Ca [(UO 2 ) 7 | (OH) 6 | (PO 4 ) 4 ] • 6H 2 O |
|
Mineral class (and possibly department) |
Phosphates, arsenates, vanadates |
|
System no. to Strunz and to Dana |
8.EC.10 ( 8th edition : VII / E.07) 6/22/12/01 |
| Crystallographic Data | |
| Crystal system | orthorhombic |
| Crystal class ; symbol | orthorhombic-dipyramidal; 2 / m 2 / m 2 / m |
| Space group | Bmmb (No. 63, position 6) |
| Lattice parameters | a = 13.73 Å ; b = 15.99 Å; c = 17.33 Å Please complete the source as an individual reference |
| Formula units | Z = 8 Please complete the source as an individual reference |
| Physical Properties | |
| Mohs hardness | 3 to 4 |
| Density (g / cm 3 ) | 4.15 to 4.54 |
| Cleavage | Please complete |
| colour | yellow |
| Line color | pale yellow |
| transparency | transparent to translucent |
| shine | Resin gloss to faint diamond gloss |
| radioactivity | highly radioactive |
| Crystal optics | |
| Refractive indices |
n α = 1.666 to 1.669 n β = 1.692 to 1.703 n γ = 1.707 to 1.710 |
| Birefringence | δ = 0.041 |
| Optical character | biaxial negative |
| Axis angle | 2V = 36 to 38 ° |
| Other properties | |
| Special features | weak fluorescence under UV light |
Yingjiangite is a very rare mineral from the mineral class of " phosphates , arsenates and vanadates ". It crystallizes in the orthorhombic crystal system with the composition K 2 Ca [(UO 2 ) 7 | (OH) 6 | (PO 4 ) 4 ] · 6H 2 O, so it is chemically a water-containing potassium - calcium - uranyl phosphate.
Yingjiangite only develops small, fibrous to needle-like crystals in the micro to millimeter range or granular to massive mineral aggregates from golden yellow to pale yellow in color.
Etymology and history
The mineral was named after its type locality , Yingjiang County (Dehong) in Yunnan Province , China. It was first described in 1990 by Zhangru Chen, Zuzhu Huang and Xiaofa Gu.
classification
Already in the now obsolete but still in use 8th edition of the mineral classification by Strunz of Yingjiangit belonged to the mineral class of "phosphates, arsenates, vanadates" and then to the Department of "uranyl phosphates and Uranylvanadate" where he along with Althupit , Arsenuranylit , Bergenit , Dewindtit , Dumontit , Françoisit- (Ce) , Françoisit- (Nd) , Hügelite , Kamitugait , Kivuit , Metavanmeer log , Mundit , Phosphuranylit , Phuralumit , Phurcalit and Vanmeersscheit formed the unnamed group VII / E.07 .
The 9th edition of Strunz's mineral systematics, valid since 2001 and used by the International Mineralogical Association (IMA), also assigns yingjiangite to the class of "phosphates, arsenates and vanadates" and there in the department of "uranyl phosphates and arsenates". This section is further subdivided according to the molar ratio of uranium oxide complex (UO 2 ) and phosphate or arsenate complex (RO 4 ), so that the mineral can be found in the sub-section "UO 2 : RO 4 = 3: 2" according to its composition , where together with arsenuranylite, bergenite, dewindtite, phosphuranylite, phurcalite and renardite, the "phosphuranylite-phurcalite group" with the system no. 8.EC.10 forms.
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns yingjiangite to the class of "phosphates, arsenates, vanadates", but there in the department of "water-containing phosphates etc., with hydroxyl or halogen". Here he is to be found as the only member of the unnamed group 06/42/12 within the subdivision of " Water-containing phosphates etc. with hydroxyl or halogen with (AB) 2 (XO 4 ) Z q × x (H 2 O) ".
Crystal structure
Yingjiangite crystallizes orthorhombically in the space group Bmmb (space group no. 63, position 6) with the lattice parameters a = 13.73 Å ; b = 15.99 Å and c = 17.33 Å as well as eight formula units per unit cell .
properties
The mineral is highly radioactive due to its high uranium content of up to 63.9% and has a specific activity of around 114 k Bq / g (for comparison: natural potassium 31.2 Bq / g). Under UV light , some Yingjiangites show a weak, yellowish-green fluorescence .
Education and Locations
Yingjiangite is produced as a secondary mineral in the oxidation zone of uranium deposits . Accompanying minerals include studtite , calcurmolite , tengchongite and autunite .
In China, in addition to its type locality Yingjiang / Yunnan (Tongbiguan), the mineral was also found in Wengyuan / Guangdong (Xiazhuang). Other sites are Ostrov nad Ohří (German Schlackenwerth ) in Bohemia / Czech Republic; Oelsnitz / Vogtl. and Johanngeorgenstadt in the Ore Mountains / Germany; as well as in Delta (Utah) in the USA.
Precautions
Due to the toxicity and the strong radioactivity of the mineral, mineral samples from Yingjiangite should only be kept in dust- and radiation-proof containers, but especially never in living rooms, bedrooms or work rooms. Absorption into the body (incorporation, ingestion ) should also be prevented in any case and, for safety, direct body contact should be avoided and respiratory protection mask and gloves should be worn when handling the mineral .
See also
Web links
- Mineral Atlas: Yingjiangite (Wiki)
- handbookofmineralogy.org - Mineral data sheet on Yingjiangite (English, PDF 66.6 kB)
Individual evidence
- ↑ a b Webmineral - Yingjiangite (English)
- ↑ a b c d MinDat - Yingjiangite (English)
- ↑ Stefan Weiß: The large Lapis mineral directory . 5th edition. Christian Weise Verlag, Munich 2008, ISBN 3-921656-17-6 .