Zálesíit

Zálesíit
	Zálesíit from Pastrana , Region Murcia , Spain (image width 5 mm)
General and classification
other names	IMA 1997-009; Agardite (Ca);
chemical formula	CaCu 6 (AsO 4 ) 2 (AsO 3 OH) (OH) 6 • 3H 2 O; (Ca, Y) Cu 6 [(OH) 6 \| AsO 3 (OH, O) \| (AsO 4 ) 2 ] • 3H 2 O;
Mineral class; (and possibly department)	Phosphates, arsenates and vanadates
System no. to Strunz ; and to Dana	8.DL.15 ( 8th edition : VII / D.53) ; 42.05.01.06
Crystallographic Data
Crystal system	hexagonal
Crystal class ; symbol	hexagonal dipyramidal; 6 / m
Space group	P 6 3 / m (No. 176)
Lattice parameters	a = 15.583 Å ; c = 5.895 Å
Formula units	Z = 2
Frequent crystal faces	{100}, {001}
Twinning	after {100}
Physical Properties
Mohs hardness	2 to 3
Density (g / cm 3 )	measured: 3.49 (3); calculated: 3.50
Cleavage	not defined
Break ; Tenacity	not defined
colour	pale green, grass green
Line color	White
transparency	transparent to translucent
shine	Glass gloss, fat gloss
Crystal optics
Refractive indices	n ω = 1.688 ; n ε = 1.765
Birefringence	δ = 0.077
Optical character	uniaxial positive
Pleochroism	Weak: ω = light yellow green, ε = light green
Other properties
Chemical behavior	slowly soluble in dilute hydrochloric acid

Zálesíit (also agardite (Ca) ) is a rarely occurring mineral from the mineral class of " phosphates , arsenates and vanadates ". It crystallizes in the hexagonal crystal system with the idealized chemical composition CaCu ₆ [(OH) ₆ | AsO ₃ OH | (AsO ₄ ) ₂ ] · 3H ₂ O and is therefore a water-containing calcium - copper arsenate with additional hydroxide ions .

Zálesíit only develops microscopic crystals of about 10 to 100 micrometers in length with a hexagonal, needle-like habit . It is mostly found in the form of radial to spherical aggregates and powdery crusts of light green color with white streak color . The crystals themselves are transparent with a glass-like to grease-like sheen on the surfaces, but in aggregate form Zálesíit appears more translucent.

Etymology and history

Zálesíit handpiece from the type locality Zálesí (size: 8.0 × 5.3 × 4.6 cm)

Zálesíit was first discovered in 1997 in the uranium deposit Zálesí (Javorník) in the Czech Republic and described in 1999 by J. Sejkora, T. Rídkošil, V. Šrein, who named the mineral after its type of locality .

The synonym Agardit- (Ca) was used as a preliminary designation by some authors before the name Zálesíit was approved by the IMA / CNMNC .

classification

Since the zálesíit was only recognized as an independent mineral in 1997 and this was published in 1999, it is not listed in the outdated 8th edition of the mineral classification according to Strunz . Only in the Lapis mineral directory , which was revised and updated in 2018 by Stefan Weiß, which is still based on this classic system from Karl Hugo Strunz out of consideration for private collectors and institutional collections , the mineral received the system and mineral number. VII / D.53-30 . In the "lapis system" this corresponds to the class of "phosphates, arsenates and vanadates" and there the section "water-containing phosphates, with foreign anions", where zálesíite together with agardite (Ce) , agardite (Dy) , agardite (La) , Agardit- (Nd) , Agardit- (Y) , Calciopetersit , Goudeyit , Juanitait , Mrazekit , Mixit , Petersit- (Ce) , Petersit- (Nd) , Petersit- (Y) and Plumboagardit the "Mixit group “Educates.

The 9th edition of Strunz's mineral systematics, valid since 2001 and updated by the IMA until 2009, also assigns the zálesíit to the department of “phosphates etc. with additional anions; with H ₂ O “. However, this is further subdivided according to the relative size of the cations involved and the molar ratio of the additional anions (OH etc.) to the phosphate, arsenate or vanadate complex (RO ₄ ), so that the mineral can be classified in the sub-section “With large and medium-sized cations; (OH etc.): RO ₄ = 2: 1 “can be found where it is only found together with agardite (Ce), agardite (La), agardite (Nd), agardite (Y), calciopetersite, goudeyite , Mixit, Petersit- (Y) and Plumboagardit the "Mixit group" with the system no. 8.DL.15 forms.

The systematics of minerals according to Dana , which is mainly used in the English-speaking world , assigns the zálesíit to the class of "phosphates, arsenates and vanadates" and there to the category of "water-containing phosphates etc., with hydroxyl or halogen". Here he is the only member / together with in the " Mixit group (Arsenat series) " with the system no. 42.05.01 within the sub-section "Water-containing phosphates etc., with hydroxyl or halogen with (A) ₂ (XO ₄ ) Z _q × x (H ₂ O)".

Crystal structure

Zálesíit crystallizes hexagonally in the space group P 6 ₃ / m (space group no. 176) with the lattice parameters a = 15.583 Å and c = 5.895 Å as well as two formula units per unit cell . Template: room group / 176

properties

Zálesíit is slowly dissolving in dilute hydrochloric acid .

Education and Locations

Needle-spherical zálesíite from the "Tucumana Mine", Inca de Oro , Province of Chañaral , Región de Atacama , Chile (field of view 4 mm)

Zálesíit from the "Serpieri Mine", Agios Konstantinos , Lavrio , Greece (field of view 3 mm)

Philipsburgite (dark green) on zálesíite (light green) from the "Gold Hill Mine", Gold Hill , Tooele County (Utah, USA)

Zálesíite is secondary to the oxidation product of chalcopyrite and cobalt arsenides. As accompanying minerals may include chrysocolla , Conichalcite , Klinoklas , malachite , Tirolit , Uranophan and Zeunerit occur.

As a rare mineral formation, Zálesíit could only be proven at a few sites, whereby so far (as of 2013) around 70 sites are known. Its type locality Zálesí (Javorník) is the only known site in the Czech Republic to date.

In Germany, Zálesíit is known from several places in the Black Forest such as the Clara mine near Oberwolfach in Baden-Württemberg, Dörrmorsbach and Waldaschaff in Bavaria, Bad Lauterberg in the Harz Mountains in Lower Saxony, Gehringswalde in Saxony and from Bergmannskopf in Thuringia.

In Austria, the mineral has so far only been found in the copper mines near Altenberg in the Paternion part of the municipality of Pöllan in Carinthia as well as in the quartzite quarry near Falkenstein ( municipality of Fischbach ) and in rock samples during a tunnel construction near Unterwald (municipality of Wald am Schoberpaß ) in Styria.

So far known sites in Switzerland are Bagnes ( Bruson ), the Chriegalp valley (also Kriegalp valley ) , which belongs to the Binntal, and the Illgraben near the Illhorn in the canton of Valais.

Other locations are among others in Australia, Chile, France, Greece, Ireland, Italy, Japan, Morocco, Spain, several places in England in the United Kingdom and some places in several states of the USA.

literature

J. Sejkora, T. Rídkošil, V. Šrein: Zálesíite, a new mineral of the mixite group, from Zálesí, Rychlebské hory Mts., Czech Republic . In: New Yearbook for Mineralogy, Treatises . tape 175 , no. 2 , 1999, p. 105-124 (English).
JL Jambor, ES Grew, AC Roberts: New mineral names . In: American Mineralogist . tape 85 , 2000, pp. 1561–1565 (English, rruff.info [PDF; 393 kB ; accessed on August 10, 2019]).

Web links

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

Mineral Atlas: Zálesíit (Wiki)
Zálesíite search results. In: rruff.info. Database of Raman spectroscopy, X-ray diffraction and chemistry of minerals (RRUFF), accessed on August 10, 2019 .
American-Mineralogist-Crystal-Structure-Database - Zálesíite. In: rruff.geo.arizona.edu. Retrieved August 10, 2019 .

Individual evidence

↑ ^a ^b Malcolm Back, William D. Birch, Michel Blondieau and others: The New IMA List of Minerals - A Work in Progress - Updated: July 2019. (PDF 1713 kB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, July 2019, accessed August 10, 2019 .
↑ ^a ^b ^c ^d 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 .
↑ ^a ^b ^c A. Aruga, I. Nakai: Structure of Ca-rich agardite, (Ca _0.40 Y _0.31 Fe _0.09 Ce _0.06 La _0.04 Nd _0.01 ) Cu _6.19 [(AsO ₄ ) _2.42 (HAsO ₄ ) _0.49 ] (OH) _6:38 · 3H ₂ O . In: Acta Crystallographica . C41, 1985, pp. 161-163 , doi : 10.1107 / S0108270185003158 (English).
^ ^A ^b David Barthelmy: Zálesíite Mineral Data. In: webmineral.com. Retrieved August 10, 2019 .
↑ ^a ^b ^c Zálesíite. In: mindat.org. Hudson Institute of Mineralogy, accessed August 10, 2019 .
↑ Ernest H. Nickel, Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF 1703 kB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed April 25, 2019 .
↑ Localities for Zálesíite. In: mindat.org. Hudson Institute of Mineralogy, accessed August 10, 2019 .
↑ List of localities for Zálesíit in the Mineralienatlas and Mindat

[IMA-Liste-2019-07-1] Malcolm Back, William D. Birch, Michel Blondieau and others: The New IMA List of Minerals - A Work in Progress - Updated: July 2019. (PDF 1713 kB) In: cnmnc.main.jp. IMA / CNMNC, Marco Pasero, July 2019, accessed August 10, 2019 .

[Lapis-2] 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 .

[AMCSD-3] A. Aruga, I. Nakai: Structure of Ca-rich agardite, (Ca _0.40 Y _0.31 Fe _0.09 Ce _0.06 La _0.04 Nd _0.01 ) Cu _6.19 [(AsO ₄ ) _2.42 (HAsO ₄ ) _0.49 ] (OH) _6:38 · 3H ₂ O . In: Acta Crystallographica . C41, 1985, pp. 161-163 , doi : 10.1107 / S0108270185003158 (English).

[Webmineral-4] A ^b David Barthelmy: Zálesíite Mineral Data. In: webmineral.com. Retrieved August 10, 2019 .

[Mindat-5] Zálesíite. In: mindat.org. Hudson Institute of Mineralogy, accessed August 10, 2019 .

[IMA-Liste-2009-6] Ernest H. Nickel, Monte C. Nichols: IMA / CNMNC List of Minerals 2009. (PDF 1703 kB) In: cnmnc.main.jp. IMA / CNMNC, January 2009, accessed April 25, 2019 .

[MindatAnzahl-7] Localities for Zálesíite. In: mindat.org. Hudson Institute of Mineralogy, accessed August 10, 2019 .

[Fundorte-8] List of localities for Zálesíit in the Mineralienatlas and Mindat