Juangodoyite
| Juangodoyite | |
|---|---|
 |
|
| General and classification | |
| other names |
IMA 2004-036 |
| chemical formula | Na 2 Cu (CO 3 ) 2 |
|
Mineral class (and possibly department) |
Carbonates and nitrates - carbonates without additional anions; without H 2 O |
|
System no. to Strunz and to Dana |
5.AB.60 ( 8th edition : V / B.05-005 ("Lapis system")) 14.03.06.01 |
| Crystallographic Data | |
| Crystal system | monoclinic |
| Crystal class ; symbol | monoclinic prismatic; 2 / m |
| Space group | P 2 1 / a (No. 14, position 3) |
| Lattice parameters |
a = 6.171 Å ; b = 8.171 Å; c = 5.645 Å β = 116.23 ° |
| Formula units | Z = 2 |
| Physical Properties | |
| Mohs hardness | "soft" |
| Density (g / cm 3 ) | 2.984 (calculated) |
| Cleavage | no information in the literature |
| Break ; Tenacity | no information in the literature |
| colour | light ultramarine blue |
| Line color | blue |
| transparency | translucent |
| shine | earthy |
| Crystal optics | |
| Refractive index | n = 1.571 (calculated) |
| Other properties | |
| Chemical behavior | Easily soluble in HCl with bubbling. Insoluble in water, hydrated within a few hours to Chalkonatronit . |
| Special features | no fluorescence |
Juangodoyite is a very rarely occurring mineral from the mineral class of " carbonates and nitrates " (formerly carbonates, nitrates and borates ). It crystallizes in the monoclinic crystal system with the idealized chemical composition Na 2 Cu (CO 3 ) 2 , so from a chemical point of view it is a sodium - copper - carbonate .
Juangodoyite is only found in fine-grained pseudomorphs after chalconatronite, Na 2 Cu (CO 3 ) 2 · 3H 2 O, with the crystallites having sizes of only 5 μm. These pseudomorphs are vivid ultramarine blue , earthy crusts that can occupy areas of several square centimeters.
The type locality of the juangodoyite is the oxidation zone of the "Miniera Santa Rosa" ( coordinates of the Miniera Santa Rosa ) located 15 km southeast of the city of Iquique in the Santa Rosa-Huantajaya district in the Atacama desert , Iquique province, Tarapacá region in northern Chile .
Etymology and history
In May 2003, the Chilean mineral collector Arturo Molina Donoso discovered significant amounts of a blue mineral that he could not identify in the oxidation zone of the abandoned "Miniera Santa Rosa" in the Atacama Desert near Iquique, northern Chile. He handed over material from this find to the German mineralogist Jochen Schlüter, who quickly discovered that this mineral could not be assigned to any of the phases known at the time. After determining the required physical and crystallographic properties and chemical composition, the mineral was submitted to the International Mineralogical Association (IMA), which recognized it as a new mineral in 2004 under the provisional designation IMA 2004-036.
In 2005, Jochen Schlueter and Dieter Pohl first described this mineral scientifically as juangodoyite in the German science magazine “New Yearbook for Mineralogy, Treatises”. They named the mineral after Juan Godoy, who discovered the famous silver deposit of Chañarcillo in the Región de Atacama in Chile in 1832 .
The type material (cotypes) for juangodoyite is kept under the catalog numbers MMHH MD 210 and MMHH MD 211 in the collection of the Mineralogical Museum of the University of Hamburg in the safe of the museum.
classification
Since juangodoyite was only recognized as an independent mineral by the International Mineralogical Association (IMA) in 2004 and the discovery was only published in 2005, it is not listed in the 8th edition of the Strunz mineral classification, which has been outdated since 1977 .
In the last revised and updated Lapis mineral directory in 2018 , which is still based on this outdated system of Karl Hugo Strunz out of consideration for private collectors and institutional collections , the mineral was given the system and mineral number. V / B.05-005 . In the “Lapis system” this corresponds to the section “Anhydrous carbonates [CO 3 ] 2− , without foreign anions ”, where juangodoyite together with Eitelite , Nyerereit , Gregoryite , Fairchildite , Zemkorite , Bütschliit and Shortit form the unnamed group V / B. 05 forms.
The 9th edition of Strunz's mineral systematics, which has been valid since 2001 and updated by the International Mineralogical Association (IMA) until 2009, assigns juangodoyite to the “carbonates and nitrates” class, which has been reduced by the borates, and to the “carbonates without additional ones” Anions; without H 2 O “. This is further subdivided according to the group membership of the cations involved , so that the mineral can be found according to its composition in the sub-section "alkaline earth (and other M 2+ ) carbonates", where the unnamed group with the system no . 5.AB.60 forms.
The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns juangodoyite to the common class of "carbonates, nitrates and borates" and there in the department of "carbonates" like the outdated Strunz system. Here he is to be found as the only member of the unnamed group 14.03.06 within the sub-section " Anhydrous carbonates with a compound formula A 2+ B 2+ (CO 3 ) 2 ".
Chemism
Mean values from 16 microprobe analyzes on juangodoyite from the type locality yielded 28.27% Na 2 O; 33.77% CuO and 38.45% CO 2 (total 100.49%). On the basis of six anions, the empirical formula Na 2.08 Cu 0.98 (C 1.99 O 6 ) is calculated from the analyzes , which can be idealized to Na 2 Cu (CO 3 ) 2 . This formula is identical to the official IMA formula for juangodoyit.
The only element combination Na – Cu – C – O among the currently known minerals (as of 2019) only has juangodoyite. Chemically similar are Antipinit , KNa 3 Cu 2 (C 2 O 4 ) 4 ; Chalconatronite, Na 2 Cu (CO 3 ) 2 • 3H 2 O; Paratooite- (La) , (La, Sr, Ca) 4 CuCa (Na, Ca) 2 (CO 3 ) 8 ; Triazolit , NACU 2 (N 3 C 2 H 2 ) 2 (NH 3 ) 2 Cl 3 · 4H 2 O; Wheatleyite , Na 2 Cu (C 2 O 4 ) 2 • 2H 2 O; as well as the unnamed phase Unnamed (Na-Cu-Cl triazolate) , NaCu 2 Cl 3 [N 3 C 2 H 2 ] 2 [NH 3 ] 2 · 4H 2 O.
Crystal structure
Juangodoyite crystallizes in the monoclinic crystal system in the space group P 2 1 / a (space group no. 14, position 3) with the lattice parameters a = 6.171 Å ; b = 8.171 Å; c = 5.645 Å; and β = 116.23 ° and two formula units per unit cell .
Juangodoyit is isotype (isostructural) with synthetic sodium bis (carbonato) cuprate (II). The crystal structure of this synthetic analog of juangodoyite was determined in 1986 by EN Maslen, N. Spadaccini, KJ Watson & AH White. The adjacent representation of the structure of juangodoyit is based on their work.
| Crystal structure of juangodoyite. The black outline shows the unit cell. |
|
| Color legend: __ Na __ Cu __ C __ O |
The crystal structure of sodium bis (carbonato) cuprate (II) can best be described as a two-dimensional polymeric network of [Cu (CO 3 ) 2 2− ] ∞ , with each copper atom in an approximately square-planar environment that is defined by the four symmetry-related bridging carbonate groups is coordinated (compare also the adjacent structural representations). This two-dimensional structure of sodium bis (carbonato) cuprate (II) contrasts strongly with the chain-like structures of Na 2 Cu (CO 3 ) 2 · 3H 2 O and Cu (NH 3 ) 2 CO 3 .
properties
morphology
At its type locality, juangodoyite forms exclusively fine-grain pseudomorphoses with crystallites up to a maximum of 5 μm in size after small, latte, sky-blue chalconatronite crystals. These pseudomorphoses can occupy areas of several square centimeters. Synthesized juangodoyite crystals form small pinacoids with average dimensions of about 0.1 mm, which are slightly elongated in the direction of the c-axis [001], but have a somewhat irregular shape.
physical and chemical properties
Many physical and optical properties of juangodoyite cannot be determined due to the small grain size of the material.
The fine-grained pseudomorphoses of juangodoyite are vividly ultramarine blue, while their stroke color is indicated as blue. The surfaces of the translucent aggregates are earthy and have no characteristic gloss . No optical properties could be determined on the juangodoyite aggregates. The mean refractive index , determined via the Gladstone-Dale relationship from the empirical formula and the calculated density , is n = 1.571. The relationship, named after John Hall Gladstone and Thomas Pelham Dale , relates the refractive index to the optical constants of the molecular and elementary components.
The Mohs hardness of juangodoyite cannot be determined due to the grain size, but the material is described as "soft". The calculated density for juangodoyite is 2.984 g / cm³. Juangodoyit is neither in the short wave still in the long-wave UV light , a fluorescent .
The mineral dissolves easily in hydrochloric acid , HCl, with strong bubbling . It is insoluble in water, but hydrates to chalconatronite within a few hours.
Education and Locations
Juangodoyite forms at its type locality in the oxidation zone of a polymetallic vein deposit in the form of pseudomorphic displacements after chalconatronite. Minerals accompanying juangodoyite at the type locality are sanrománite , chalconatronite , malachite , calcite , anhydrite and sodium hydrogen carbonates (mainly trona and nahcolith ). At the only other place of discovery, the "Rudna 9 Mine" in Poland, the mineral u. a. accompanied by chalconatronite and covelline .
As a very rare mineral formation, juangodoyite is only known from a few localities or in a small number of stages. So far (as of 2019), the mineral has been described by only one other location in addition to its type locality. The type locality of juangodoyite is the "Miniera Santa Rosa" located 15 km southeast of the city of Iquique in the Santa Rosa-Huantajaya district in the Atacama desert , province of Iquique, Región de Tarapacá in northern Chile , where the mineral is found in larger quantities than in- situ formation was found in the oxidation zone of the deposit. The "Miniera Santa Rosa" is a polymetallic vein deposit that was primarily mined for the silver, copper and lead minerals found there. The last activity in this mine dates back to 1945.
The only other site for juangodoyite is the "Rudna 9 Mine", Gmina Polkowice , Powiat Polkowicki , Lower Silesian Voivodeship , Poland . Locations from Germany , Austria and Switzerland are therefore unknown.
use
Apart from the interest of the mineral-collecting community in this mineral, juangodoyite is completely insignificant from an economic point of view.
See also
literature
- Jochen Schlüter, Dieter Pohl: Juangodoyite, Na 2 Cu (CO 3 ) 2 , a new mineral from the Santa Rosa mine, Atacama desert, Chile . In: New Yearbook for Mineralogy, Treatises . tape 182 , no. 1 , 2005, p. 11-14 , doi : 10.1127 / 0077-7757 / 2005/0026 .
- Juangodoyite . In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America . 2001 ( handbookofmineralogy.org [PDF; 87 kB ; accessed on November 25, 2019]).
Web links
- Mineral Atlas: Juangodoyite (Wiki)
- Juangodoyite. In: mindat.org. Hudson Institute of Mineralogy, accessed November 25, 2019 .
- David Barthelmy: Juangodoyite Mineral Data. In: webmineral.com. Retrieved November 25, 2019 .
- Juangodoyite search results. In: rruff.info. Database of Raman spectroscopy, X-ray diffraction and chemistry of minerals (RRUFF), accessed on November 25, 2019 .
- American-Mineralogist-Crystal-Structure-Database - Juangodoyite. In: rruff.geo.arizona.edu. Retrieved November 25, 2019 .
Individual evidence
- ↑ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac Jochen Schlüter, Dieter Pohl: Juangodoyite, Na 2 Cu (CO 3 ) 2 , a new mineral from the Santa Rosa mine, Atacama desert, Chile . In: New Yearbook for Mineralogy, Treatises . tape 182 , no. 1 , 2005, p. 11-14 , doi : 10.1127 / 0077-7757 / 2005/0026 .
- ↑ Juangodoyite . In: John W. Anthony, Richard A. Bideaux, Kenneth W. Bladh, Monte C. Nichols (Eds.): Handbook of Mineralogy, Mineralogical Society of America . 2001 ( handbookofmineralogy.org [PDF; 87 kB ; accessed on November 25, 2019]).
- ↑ Type mineral catalog Germany - storage of the type level juangodoyit. In: typmineral.uni-hamburg.de. Mineralogical Museum of the University of Hamburg, accessed on November 25, 2019 .
- ↑ 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 .
- ↑ Ernest H. Nickel, Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF 1703 kB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed September 25, 2019 .
- ↑ Malcolm Back, William D. Birch, Michel Blondieau and others: The New IMA List of Minerals - A Work in Progress - Updated: September 2019. (PDF 2692 kB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, September 2019, accessed October 4, 2019 .
- ↑ Minerals with Na, Cu, C, O. In: mindat.org. Hudson Institute of Mineralogy, accessed November 25, 2019 .
- ↑ a b EN Maslen, N. Spadaccini, KJ Watson, AH White: Electron density in non-ideal metal complexes. II. Sodium bis (carbonato) cuprate (II) . In: Acta Crystallographica Section B . tape 42 , no. 5 , 1986, pp. 430-436 , doi : 10.1107 / S0108768186097926 (English).
- ^ Anthony K. Gregson, Peter C. Healy: Ferromagnetic interactions in sodium bis (carbonato) cuprate (II) . In: Inorganic Chemistry . tape 17 , no. 10 , 1978, p. 2969-2970 , doi : 10.1021 / ic50188a060 (English).
- ↑ a b c Juangodoyite. In: mindat.org. Hudson Institute of Mineralogy, accessed November 25, 2019 .
- ↑ Localities for Juangodoyite. In: mindat.org. Hudson Institute of Mineralogy, accessed November 25, 2019 .
- ↑ a b List of locations for juangodoyite in the Mineralienatlas and Mindat (accessed on November 25, 2019)