Papagoite

The mineral Papagoite is a very rare ring silicate with the chemical composition Ca2Cu2Al2 [( OH) 6 | Si4O12 ]. It crystallizes in the monoclinic crystal system and usually developed slightly to the {100 } flattened, sky-blue crystals of up to about three millimeters in size. But more often are foliated or microcrystalline, radial- aggregates and crusty coatings or inclusions in quartz.

With a Mohs hardness from 5 to 5.5 of Papagoite belongs to the medium-hard minerals that can be similar to the reference mineral apatite carve with the knife still. Visible crystal faces have a glass-like shine.

Etymology and history

Was first discovered Papagoite in the "New Cornelia Mine" (also Ajo Mine) at Ajo in Pima County in the U.S. state of Arizona and described in 1960 by C. Osborne Hutton and Angelina C. Vlisidis that the minerals by living in the Fund field Tohono O ' Odham (Spanish: Papago ).

Classification

In the now outdated but still in use 8th edition of the mineral classification by Strunz the Papagoite belonged to the mineral class of " silicates and Germanates " and then to the Department of " ring silicates ( cyclo- silicates) ", where he formed a distinct group with Ashburtonit.

The 9th edition valid since 2001 and of the International Mineralogical Association (IMA ) used the Strunz'schen Mineral classification assigns the Papagoite also included in the category of " silicates and Germanates " and then in the Department of the " ring silicates ( cyclo- silicates) ." This division, however, is further subdivided according to the nature of the silicate ring formation and the possible presence of other anions, so that the mineral according to its structure and composition in the subdivision - is to find " [ Si4O12 ] 8 four - Simple rings without insular complex anions " where it forms the unnamed group 9.CE.05 the only member.

The mainly common in English-speaking classification of minerals according to Dana assigns the Papagoite in the class of " silicates and Germanates " and then in the Department of the " ring silicates: four rings " one. Here he is the only member of the unnamed group 60.01.04 within the subdivision: to find the " ring silicates four rings as titanosilicates ".

Education and Locations

Papagoite forms as a secondary mineral in small veins within granodiorite porphyries, mostly in paragenesis with Ajoit, Aurichalcit, barite, quartz, and Shattuckit.

Overall, Papagoite so far (as of 2011) are detected at seven localities. Apart from the type locality " New Cornelia Mine" ( Ajo Mine) at Ajo in the U.S., these are still the " Sinclair Mine" in the Karas Region of Namibia, Košice in eastern Slovakia as well as the " Messina Mine" ( Musina mine ) and the region of Musina in South Africa.

Crystal structure

Papagoite crystallizes in the monoclinic space group C2 / m ( Raumgruppen-Nr. 12) with the lattice parameters a = 12.93 Å; b = 11.50 Å; c = 4.70 Å and 100.8 ° and β = 2 formula units per unit cell.