Ye'elimite

  • Yeélimit
  • Yeelimit
  • IMA 1984-052

Ye'elimit (also Yeélimit or Yeelimit ) is a very rare occurring mineral from the mineral class of " sulfates ( and Related ) ". It crystallizes in the cubic crystal system with the chemical composition Ca4Al6 [ O12 | SO4 ] and has so far been found only in the form of translucent, colorless to white mineral aggregates consisting of up to 15 micron sized crystals.

Special Features

Ye'elimit hydrated easily and changes in the water ( H2O) to ettringite ( Ca6Al2 [( OH) 12 | (SO4 ) 3] · 26 H2O) and Al ( OH) 3 at.

Etymology and history

Was first discovered Ye'elimit Har Je'elim (English: Har Ye'elim ) in Israel and described in 1984 by S. Gross, who named the mineral after its type locality.

Classification

In the now outdated but still in use 8th edition of the mineral classification by Strunz the Ye'elimit to the mineral class of " sulfates, selenates, tellurates, chromates, molybdates and tungstates " belonged and there to the Department of " water clear sulfates with foreign anions ", where he formed a distinct group along with D' Ansit.

The 9th edition used since 2001 and valid by the International Mineralogical Association (IMA ) of the Strunz'schen Mineral classification assigns the Ye'elimit in the class of " sulfates ( selenates, tellurates, chromates, molybdates and tungstates ) " and then in the Department the " sulfates ( selenates, etc.) with other anions, without H2O" a. This division, however, is further divided according to the 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.BC.15 the only member.

The mostly commonly used in English-speaking classification of minerals according to Dana assigns the Ye'elimit in the class of " sulfates, chromates and molybdates " and there in the department of " water clear sulfates with hydroxyl or halogen" one. Here he is the only member of the unnamed group 30.01.15 within the sub-division of " water clear sulfates with hydroxyl or halogen, and (AB ) m ( XO4 ) PZQ, with m: p> 2: 1" to find.

Education and Locations

Ye'elimit is part of a high-temperature mineral association, which consists of the minerals Larnit, brownmillerite, Ellestadit and Ye'elimit. The formation conditions of> 900 ° C at low pressure in accordance with the Sanidinitfazies.

In nature Ye'elimit has been found only in the vicinity of Har Je'elim and Nahal Je'elim in Hatrurim Basin in Israel as well as in a basalt quarry in Klöch in the Austrian district of Southeastern Styria (Steiermark). Another find point that Absetzerhalde in Ronneburg today no longer exists.

Crystal structure

Ye'elimit crystallized cubic in space group I4132 ( Raumgruppen-Nr. 214 ) with the lattice parameters a = 18.39 Å, and 16 formula units per unit cell.

Use

Economic importance (after construction chemical notation C4A3S, also calcium sulfoaluminate, CSA, or " Klein's compound" called ) in cement production Ye'elimit. In Sulfataluminatzementen Ye'elimit is the most important reactive component. In the presence of water and slightly soluble sulfate, such as in the form of anhydrite, gypsum or bassanite, he transforms into water-containing ettringite, which forms a stable microstructure is composed of needle-like, interlocked crystals during hardening. Is industrially produced Ye'elimit -containing cement clinker from a mixture of limestone, bauxite and natural or synthetic gypsum or anhydrite or calcium -, aluminum- and sulfur-containing secondary raw materials, which are fired in rotary kilns at temperatures between 950 ° C and 1350 ° C.

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