Liebigit

Liebigit
Liebigit from the Schwartzwalder Mine, Colorado, USA
General and classification
other names	Flutherite Hebergite Calcuric carbonate Uranothallite
chemical formula	Ca 2 (UO 2 ) (CO 3 ) 3 · 11H 2 O Ca 2 [UO 2 | (CO 3 ) 3 ] • (8 + 3) H 2 O
Mineral class (and possibly department)	Carbonates and Nitrates (8th edition: Carbonates and Borates)
System no. to Strunz and to Dana	5.ED.20 ( 8th edition : Vb / D.04) 03/15/02/01
Crystallographic Data
Crystal system	orthorhombic
Crystal class ; symbol	orthorhombic-pyramidal; mm 2
Space group	Bbe 2 (No. 41, position 2)
Lattice parameters	a  = 16.70  Å ; b  = 17.56 Å; c  = 13.70 Å
Formula units	Z  = 8
Physical Properties
Mohs hardness	2 to 3
Density (g / cm 3 )	2.41
Cleavage	clearly {100}
Break ; Tenacity	uneven
colour	yellow, yellow-green, green
Line color	light green
transparency	transparent to translucent
shine	Glass gloss
radioactivity	highly radioactive
Crystal optics
Refractive indices	n α  = 1.497 n β  = 1.502 n γ  = 1.539
Birefringence	δ = 0.042
Optical character	biaxial positive
Axis angle	2V = 37 to 42 °
Pleochroism	visible: X = almost colorless; Y and Z = light yellowish green
Other properties
Special features	strong green to blue-green fluorescence

Liebigit is a rarely occurring mineral from the mineral class of " carbonates and nitrates " (formerly "carbonates, nitrates and borates ") with the chemical composition Ca ₂ [UO ₂ | (CO ₃ ) ₃ ] · (8 + 3) H ₂ O making it chemically seen a hydrous calcium - uranyl carbonate .

Liebigite crystallizes in the orthorhombic crystal system and develops mostly leafy or granular mineral aggregates and crusty coatings, but rarely also tabular to short prismatic crystals up to 5 mm in size and yellow-green in color. The crystals are transparent to translucent and have a glass-like sheen on the crystal surfaces .

Etymology and history

Liebigit was first found near Edirne (previously: Adrianople ) in Turkey and described in 1848 by John Lawrence Smith (1818-1883), who named the mineral in honor of the German chemist Justus von Liebig after him.

The type material of the mineral is in the American Museum of Natural History in New York City (USA) under the catalog no. 16847 kept.

classification

In the now outdated 8th edition of the mineral classification according to Strunz , the Liebigite belonged to the common mineral class of "carbonates, nitrates and borates" and there to the department "Hydrous carbonates with foreign anions ", where together with andersonite , bayleyite , metazellerite , rabbittite , rutherfordin , Schröckingerit , Sharpit , Studtit , Swartzit , Voglit , Wyartit and Zellerit formed the "group of uranyl carbonates" Vb / D.04 .

In the last revised and updated Lapis mineral directory by Stefan Weiß in 2018 , which, out of consideration for private collectors and institutional collections, is still based on this classic system of Karl Hugo Strunz , the mineral was given the system and mineral number. V / F.02-70 . Also in the "Lapis system" this corresponds to the common mineral class of "carbonates, nitrates and borates", but there the department "Uranyl carbonates [UO ₂ ] ²⁺ - [CO ₃ ] ^2- ", where the Liebigit together with agricolaite , Andersonite, Bayleyit, Čejkait , Fontanit , Grimselit , Leoszilardit , Metazellerit forms a separate, but unnamed group Swartzit and Zellerit.

Since the complete revision of Strunz's mineral systematics in the 9th edition (2001), the mineral class of carbonates (and relatives) has been redistributed and the borates form a class of their own. The Liebigit is accordingly to be found in the mineral class of "carbonates and nitrates" and there in the still existing department of "uranyl carbonates". This, however, is further divided by the molar ratio of the uranyl - cation (UO ₂ ²⁺ ) to carbonate - anion (CO ₃ ^2- ), which when liebigite 1: 4. Liebigit is the only member of this subdivision to form the unnamed group 5.ED.20 .

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the Liebigit to the common class of "carbonates, nitrates and borates" like the outdated Strunzian system. There, however, the Liebigit is in the department of “Hydrogenous Carbonates” and the subdivision of “ Hydrogenous Carbonates with the general composition A ⁺ _m B ²⁺ _n (XO ₃ ) _p  • x (H ₂ O), the ratio (m + n ): p = 1: 1 and with U, Th, Zr, Y “, where he is the only member of the unnamed group 03/15/02 .

Crystal structure

Liebigit crystallizes orthorhombically in space group Bbe 2 (space group no. 41, position 2) with the lattice parameters a  = 16.70  Å ; b  = 17.56 Å; c  = 13.70 Å and 8 formula units per unit cell .

The crystal structure of Liebigit consists of [UO ₂ | (CO ₃ ) ₃ ] ^4- assemblies, which are connected to one another via CaO ₄ (H ₂ O) ₄ polyhedra. On the one hand, these connections form zigzag chains parallel to the c-axis [001] and straight chains parallel to the a-axis [100]. The result is "wrinkled" layers parallel to the surface (010) or perpendicular to the b-axis.

properties

The mineral is radioactive due to its uranium content of up to 32.7% . Taking into account the proportions of the radioactive elements in the idealized empirical formula and the Folgezerfälle the natural decay series a is for the mineral specific activity of about 58.5 k Bq stated / g (compared to natural potassium 0.0312 kBq / g). The quoted value can vary significantly depending on the mineral content and composition of the levels; selective enrichment or depletion of the radioactive decay products is also possible and changes the activity.

Under short- and long-wave UV light , Liebigit shows a blue-green fluorescence , which was examined more closely on synthetic material.

Education and Locations

Liebigite from the Bjertnes pegmatite at Lake Krøderen in Norway (field of view 6 × 4 cm)

Liebigite forms as a secondary mineral usually by weathering of uraninite in the presence of alkaline carbonate solutions. In addition to uraninite, accompanying minerals are other uranium minerals such as autunite , bayleyite , carnotite , schröckingerite , tyuyamunite , uranophane , uranophane-beta , but also gypsum and calcite .

As a rare mineral formation, Liebigite could only be detected in a few places worldwide, with around 90 locations being documented so far (status: 2019). Its type locality Edirne ( Adrianople ) is the only place of discovery in Turkey so far.

In Germany, Liebigit performed in the Kirchheimer adit near the Müllenbach uranium deposit near Baden-Baden in Baden-Württemberg; at the Fuchs quarry on the Hartkoppe near Sailauf ( Hösbach ), in the quartz quarry near Altrandsberg in the municipality of Miltach and in the Höhenstein and Wäldel shafts of the Mähring uranium deposit in Bavaria; near Eisleben in Saxony-Anhalt; in several places near Schneeberg and Johanngeorgenstadt in Saxony and near Beerwalde / Löbichau and Schmirchau near the uranium deposit of Ronneburg in Thuringia.

In Austria, the mineral was found in the excavated material of the Kölnbrein reservoir of the Maltakraftwerke in Carinthia as well as the Tauern tunnel in the Anlauftal , the spa casino near Bad Gastein and the Bockhart tunnel near Siglitz in the Gastein Valley in Salzburg.

Other locations are in Australia , China , France , Italy , Japan , Canada , the Democratic Republic of the Congo , Norway , Sweden , the Czech Republic , Turkey , Hungary , the United Kingdom (Great Britain) and the United States of America (USA).

Precautions

Due to the toxicity and the strong radioactivity of the mineral, mineral samples from Liebigit should only be kept in dust- and radiation-proof containers, but above all never in living rooms, bedrooms or workrooms. 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

• List of minerals

literature

• Howard T. Evens, Jn., Clifford Frondel: Studies of Uranium Minerals (II) - Liebigite and Uranothallite . In: American Mineralogist . Archive volume 35, March – April, 1950 ( minsocam.org [PDF; 245 kB ; accessed on April 26, 2019]).
• Heinz Meixner , Kurt Walenta : Liebigit, a uranium carbonate mineral new for Austria from the Kölnbreinsperre, Maltaltal, Carinthia . In: The Karinthin . Episode 81. Knappenberg 1979, p. 151-153 .
• K. Mereiter: The crystal structure of Liebigite, Ca ₂ UO ₂ (CO ₃ ) ₃ · ~11 H ₂ O . In: Tschermaks mineralogical and petrographic communications . tape 30 , 1982, chap. 4 , p. 277-288 , doi : 10.1007 / BF01087173 .

• Friedrich Klockmann : Klockmann's textbook of mineralogy . Ed .: Paul Ramdohr , Hugo Strunz . 16th edition. Enke, Stuttgart 1978, ISBN 3-432-82986-8 , pp. 584 (first edition: 1891).

Web links

Commons : Liebigite  - collection of images, videos and audio files

• Mineral Atlas: Liebigit (Wiki)
• Liebigite search results. In: rruff.info. Database of Raman spectroscopy, X-ray diffraction and chemistry of minerals (RRUFF), accessed April 26, 2019 . 
• American-Mineralogist-Crystal-Structure-Database - Liebigite. In: rruff.geo.arizona.edu. Retrieved April 26, 2019 . 

Individual evidence

1. ↑ Malcolm Back, William D. Birch, Michel Blondieau and others: The New IMA List of Minerals - A Work in Progress - Updated: March 2019. (PDF 1703 kB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, March 2019, accessed April 27, 2019 .  
2. ↑ ^{a b c d e f} Hugo Strunz , Ernest H. Nickel : Strunz Mineralogical Tables. Chemical-structural Mineral Classification System . 9th edition. E. Schweizerbart'sche Verlagbuchhandlung (Nägele and Obermiller), Stuttgart 2001, ISBN 3-510-65188-X , p.  321 (English).
3. ↑ ^{a b} David Barthelmy: Liebigite Mineral Data. In: webmineral.com. Retrieved April 26, 2019 .  
4. ↑ ^{a b} The former name of this room group was Bba 2.
5. ↑ ^{a b c d e f} Liebigite . In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America . 2001 (English, handbookofmineralogy.org [PDF; 68  kB ; accessed on April 26, 2019]).
6. ↑ ^{a b c d e f} Liebigite. In: mindat.org. Hudson Institute of Mineralogy, accessed April 26, 2019 .  
7. ^ William H. Brock: Justus Von Liebig: The Chemical Gatekeeper . Cambridge University Press, Cambridge 1997, ISBN 0-521-56224-4 , pp. 349 (English, limited preview in Google Book Search [accessed April 26, 2019]).
8. ↑ J. Laurence Smith: Two new minerals - Medjidit (sulfuric uranium oxide lime) - Liebigite (carbonate uranium oxide lime) . In: Justus Liebig's Annals of Chemistry . tape 66 , No. 2, 1848, pp. 253-256 ( limited preview in Google Book Search [accessed April 26, 2019]).
9. ↑ J. Lawrence Smith: Two new minerals, - medjidite (sulphate of uranium and lime) - liebigite (carbonate of uranium and lime) . In: The American Journal of Science and Arts . tape 5 , May 1848, p. 336–338 (English, rruff.info [PDF; 221 kB ; accessed on April 26, 2019]).
10. ↑ Stefan Weiß: The large Lapis mineral directory. All minerals from A - Z and their properties. Status 03/2018 . 7th, completely revised and supplemented edition. Weise, Munich 2018, ISBN 978-3-921656-83-9 .
11. ↑ Renaud Vochen, Laurent van Haverbeke, Karel van Springel: Synthesis of liebigite and andersonite, and study of their thermal behavior and luminescence . In: The Canadian Mineralogist . tape 31 , 1993, pp. 167–171 (English, rruff.info [PDF; 648 kB ; accessed on April 26, 2019]).
12. ↑ Localities for Liebigite. In: mindat.org. Hudson Institute of Mineralogy, accessed April 26, 2019 .  
13. ↑ Find location list for Liebigit in the Mineralienatlas and in Mindat