TY - JOUR

T1 - Gunterblassite, (K,Ca)(3-x) Fe[(Si,Al)(13)O-25(OH,O)(4)] center dot 7H(2)O, a new mineral: the first phyllosilicate with triple tetrahedral layer

AU - Chukanov, N.V.

AU - Rastsvetaeva, R.K.

AU - Aksenov, S.M.

AU - Pekov, I.V.

AU - Zubkova, N.V.

AU - Britvin, S.N.

AU - Belakovskiy, D.I.

AU - Schüller, W.

AU - Ternes, B.

PY - 2012

Y1 - 2012

N2 - A new mineral, gunterblassite, has been found in the basaltic quarry at Mount Rother Kopf near Gerolstein, Rheinland-Pfalz, Germany as a constituent of the late assemblage of nepheline, leucite, augite, phlogopite, Ayenkermanite, magnetite, perovskite, a lamprophyllite-group mineral, gotzenite, chabazite-K, chabazite-Ca, phillipsite-K, and calcite. Gunterblassite occurs as colorless lamellar crystals up to 0.2 x 1 x 1.5 mm in size and their clusters. The mineral is brittle, with perfect cleavage parallel to (001) and less perfect cleavage parallel to (100) and (010). The Mohs hardness is 4. The calculated and measured density is 2.17 and 2.18(1) g/cm(3), respectively. The IR spectrum is given. The new mineral is optically biaxial and positive as follows: alpha = 1.488(2), beta = 1.490(2), gamma = 1.493(2), 2V (meas) = 80(5)A degrees. The chemical composition (electron microprobe, average of seven point analyses, H2O is determined by gas chromatography, wt %) is as follows: 0.40 Na2O, 5.18 K2O, 0.58 MgO, 3.58

AB - A new mineral, gunterblassite, has been found in the basaltic quarry at Mount Rother Kopf near Gerolstein, Rheinland-Pfalz, Germany as a constituent of the late assemblage of nepheline, leucite, augite, phlogopite, Ayenkermanite, magnetite, perovskite, a lamprophyllite-group mineral, gotzenite, chabazite-K, chabazite-Ca, phillipsite-K, and calcite. Gunterblassite occurs as colorless lamellar crystals up to 0.2 x 1 x 1.5 mm in size and their clusters. The mineral is brittle, with perfect cleavage parallel to (001) and less perfect cleavage parallel to (100) and (010). The Mohs hardness is 4. The calculated and measured density is 2.17 and 2.18(1) g/cm(3), respectively. The IR spectrum is given. The new mineral is optically biaxial and positive as follows: alpha = 1.488(2), beta = 1.490(2), gamma = 1.493(2), 2V (meas) = 80(5)A degrees. The chemical composition (electron microprobe, average of seven point analyses, H2O is determined by gas chromatography, wt %) is as follows: 0.40 Na2O, 5.18 K2O, 0.58 MgO, 3.58

U2 - 10.1134/S1075701512080065

DO - 10.1134/S1075701512080065

M3 - Article

VL - 54

SP - 656

EP - 662

JO - Geology of Ore Deposits

JF - Geology of Ore Deposits

SN - 1075-7015

IS - 8

ER -