Niedermayrite
- IMA 1997-024
Niedermayrit is a very rarely occurring mineral from the mineral class of hydrous sulfates with foreign anions. It crystallizes in the monoclinic crystal system with the chemical composition CdCu4 [( OH) 6 | (SO4 ) 2] · 4H2O and usually develops massive aggregates and crusty coatings in blue-green color.
Special Features
By heating the mineral loses in two stages at about 100 to 300 ° C may be crystal water.
Etymology and history
Niedermayrit first time in 1995 was found by F. Schreiber in the type locality in the mining area of Laurion in Greece and described by G. Giester, B. Rieck and F. Brandstätter. They named it after the Austrian mineralogist and curator of the mineralogical collection of the Natural History Museum Vienna Gerhard Mayr Low ( b. 1941 ).
Classification
In the old ( 8th edition ) and new classification of minerals according to Strunz ( 9th edition ) of the Niedermayrit belongs to the department of the " water -containing sulfates with foreign anions ." The new Strunz'sche Mineral classification divided here, however, precisely according to the size of the cations involved, and therefore the mineral is now appropriately in the subdivision " with medium-sized cations and edge-sharing octahedra ," where he Campigliait, Devillin, Lautenthalit, Orthoserpierit and Serpierite Group 7 forms. DD.30.
The commonly used in English-speaking classification of minerals according to Dana assigns the Niedermayrit also in the class of sulfates, there, however, in the department of " water -containing sulfates having hydroxyl and halogen groups having the general formula (A B2 ) 5 ( XO4 ) 2 Zq × x (H2O) "where he is the unnamed group 31.06.06 with Campigliait.
Education and Locations
Probably Niedermayrit, as a secondary mineral as aging product of Greenockit and chalcopyrite. The matrix consists of marble interspersed with sphalerite, chalcopyrite, galena, Greenockit, Hawleyit and pyrite. Other minerals, which Niedermayrit is associated, are the secondary minerals gypsum, malachite, Chalkanthit, Brochantite, hemimorphite Hydrozincite, Aurichalcit, Monteponit and Otavit.
There are so far only three finds of Niedermayits known. It consists of two mines at Laurion in Greece and the Hidden Treasure mine at Ophir in the U.S. state of Utah.
Crystal structure
Niedermayrit crystallizes in the monoclinic crystal system, space group P21 / m with lattice parameters a = 5.543 Å; b = 21.995 Å; c = 6.079 Å and β = 92.04 ° and two formula units per unit cell.