Aphthitalite
- Formerly glaserite
Aphthitalit (formerly glaserite ) or Schwefelkalisalz, is a rarely occurring mineral from the mineral class of " sulfates " ( and relatives, see Classification ). It crystallizes in the trigonal crystal system with the chemical composition K3Na [ SO4 ] 2 and developed thin to dicktafelige, up to seven inches large crystals with trigonal or by multiple twinning pseudo- orthorhombic habit, but also foliated mineral aggregates or crusty coatings.
Reiner Aphthitalit is colorless, but it can also appear white due to lattice defects and foreign inclusions or accept by foreign admixtures a gray, bluish, greenish or reddish color.
Special Features
The mineral is soluble in water and salty to bitter taste.
Etymology and history
Was first found Aphthitalit 1832 at Vesuvius in Italy and described by François Sulpice Beudant, who named the mineral in terms of its durability and stability even in the air after the Greek words immutable and salt.
Regardless of Beudant also described Friedrich Hausmann in 1847, the same mineral, and gave him in honor of the French chemist and pharmacologist Christophe Glaser name glaserite. This name was later withdrawn after examination by the CNMNC (Commission on new Minerals, Nomenclature and Classification, International Mineralogical Association see ). Because the law was on naming the first to describe Beudant.
Classification
In the now outdated but still in use 8th edition of the mineral classification by Strunz the Aphthitalit belonged to the mineral class of " sulfates, chromates, molybdates, tungstates " and then to the Department of " Anhydrous sulfates [ SO4 ], without other anions ", where he with anhydrite, glauberite, Kalistrontit and Palmierit the unnamed group VI/A.08 formed.
The 9th edition valid since 2001 and of the International Mineralogical Association (IMA ) used the Strunz'schen Mineral classification assigns the Aphthitalit in the extended class of " sulfates ( selenates, tellurates, chromates, molybdates and tungstates ) ," there but also in the Department of " sulfates ( selenates, etc. ) without additional anions, without H2O" one. However, this is further divided according to the relative size of the cations involved, so that the mineral is found according to its composition in the subsection "With medium -sized and large cations ", where it forms the unnamed group 7.AC.35 the only member.
The mainly common in English-speaking classification of minerals according to Dana assigns the Aphthitalit in the class of " sulfates, chromates and molybdates " and there in the department of " sulfates " one. Here he is " 2XO4 water outdoors acids and sulfates of the general formula (A )" to find the only member / along with the unnamed group 28.02.02 within the subdivision.
Education and Locations
Aphthitalit either forms of fumaroles, where it occurs in the form of crusts or in crystalline form in marine and continental evaporite or guano deposits. Depending on the conditions of formation it is then found in paragenesis with various other Alan Miner, so among other things, hematite, jarosite, sylvite and thenardite at fumaroles; Blödite, borax, halite, mirabilite, and Pikromerit syngenite in evaporites; or syngenite, whitlockite, Monetit, Nitrokalit and gypsum in guano.
Could Worldwide Aphthitalit so far (as of 2010) are detected at nearly 40 sites, so including Australia, China, Germany, France, Iceland, Iran, Italy, Japan, Norway, Austria, Peru, Russia, Saudi Arabia, Ukraine, United States and the United Kingdom ( UK).
Crystal structure
Aphtitalit trigonal crystallized in the space group P3m1 ( Raumgruppen-Nr. 164) with the lattice parameters a = 5.68 Å and c = 7.309 Å and a formula units per unit cell.