Bazzite

The mineral Bazzit is a rarely occurring ring silicate from the beryl group. It crystallizes in the hexagonal crystal system with the composition Be3 (Sc, Al, Fe3 ) 2 [ Si6O18 ] • NA0, 32 • nH2O, that is chemically a hydrous silicate of beryllium ring. The values ​​given in the parentheses elements scandium, aluminum and iron can relax in the formula each represent each other ( Diadochie ), but are always in the same proportions to the other components of the mineral.

Bazzit usually develops translucent, prismatic to columnar crystals to about 2 cm in length with a hexagonal habit, but also radial- mineral aggregates from light blue to dark blue color with white stroke color. A Moh's hardness 6.5 to 7 Bazzit one of the hard minerals, which are similar to the reference mineral quartz ( 7) in a position to scribe simple window glass.

Etymology and history

Bazzit was first discovered in the " Seula Mine" at Monte Camoscio near Oltrefiume ( Baveno community ) in the Italian region Piedmont and described in 1915 by E. Artini, who named the mineral after its discoverer E. Alessandro Bazzi.

Classification

Already in the now outdated but still in use 8th edition of the mineral classification by Strunz was one of Bazzit to the mineral class of " silicates and Germanates " and then to the Department of " ring silicates ( cyclo- silicates) ," where he along with beryl, cordierite, Indialith, Pezzottaite, Sekaninait and Stoppaniit formed a distinct group.

The 9th edition valid since 2001 and of the International Mineralogical Association (IMA ) used the Strunz'schen Mineral classification assigns the Bazzit 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 by the type of ring formation, so that the mineral according to its construction in the subdivision - is to find " [ Si6O18 ] 12 six- Simple rings without insular complex anions " where there is only together with beryl, indialite, Pezzottaite and Stoppaniit the " beryl " with the system no. 9.CJ.05 forms.

The mainly common in English-speaking classification of minerals according to Dana assigns the Bazzit in the class of " silicates and Germanates " there, however, in the fine already divided the department " ring silicates: Six Rings " field. He is also a member of the " beryl " with the system no. 61.01.01 and the other members beryl, Indialith, Stoppaniit and Pezzottaite within the subdivision of the " ring silicates: Six rings with Si6O18 rings; possible (OH ) and find Al- substitution ".

Education and Locations

Bazzit formed by hydrothermal processes in alpinotype, scandium- pegmatite dykes and miarolitischen clefts in the granite. Accompanying minerals include albite, Bavenit, beryl, calcite, chlorite, fluorite, hematite, laumontite, muscovite, orthoclase and quartz.

A rare mineral formation Bazzit has so far (as of 2011) are detected only at a few localities, of which about 40 can be regarded as well-known addition to its type locality " Seula Mine" came the mineral in Italy or in the community Cuasso al Monte in Lombardy and in Agrano ( Omegna ) on in Piedmont. Another site on the Petit Mont Blanc in Val Veny has been questionable.

Noteworthy due to exceptional Bazzitfunde among other Tordal in the Norwegian municipality Drangedal, where up to two inches long crystals were found.

In Germany, the mineral found in the quarry Steinerleinbach at Roehrnbach in Saldenburg - Matzersdorf and Tittling - supporters village in Bavaria and the First Stone at Königshain, at the motorway tunnel in the A 4 at Thiemendorf and the quarry new ground in Döbschütz in Saxony.

In Austria Bazzit has only been found at the Gjaidtroghöhe in the Great Fleißtal in Carinthia. In Switzerland, the mineral occurred in Bern, Grisons community Sedrun, at several locations in the Gotthard massif in Ticino, in Etzlital and Gurtnellen in the Canton of Uri, and at several locations in the canton of Valais at Oberaarsee.

Other localities lie in France, Japan, Kazakhstan, Russia and the United States.

Crystal structure

Bazzit crystallized hexagonal space group P6/mcc ( Raumgruppen-Nr. 192) with the lattice parameters a = 9.51 Å and c = 9.11 Å and two formula units per unit cell.