Chukanov N. V., Kasatkin A. V., Zubkova N V., Britvin S. N., Pautov L. A., Pekov I. V.t Varlamov D. Α., Bychkova Ya. V., Loskutov A. В., Novgorodova Ε. A.

Tatarinovite Ca3Al(SO4)[В(ОН)4](ОН)6・12Н2О — a new ettringite-group mineral from the Bazhenovskoe deposit (the Middle Urals,Russia), and its crystal structure

Zapiski RMO (Proceedings of the Russian Mineralogical Society). 2016. V. 145. N 1. P. 48-67

Full text is available

Language: Russian

Abstract

A new mineral tatarinovite, ideally Ca3Al(SO4)[В(ОН)4](ОН)6・12Н2О, has been found in cavities of rhodingites at the Bazhenovskoe chrysotile asbestos deposit, the Middle Urals, Russia. It occurs (1) as colorless, with vitreous luster, dipyramidal crystals up to 1 mm across in cavities within massive diopside, in association with xonotlite, clinochlore, pectolite and calcite, and (2) as white granular aggregates, up to 5 mm in size, on grossular with pectolite, diopside, calcite and xonotlite. Mohs’ hardness is 3; perfect cleavage on (100) is observed. Dmeas 1.79(1), Dcalc 1.777 g/cm3. Tatarinovite is optically uniaxial (+),  = 1.475(2),  = 1.496(2). The IR spectrum contains characteristic bands of  , ,  , B(OH)3, , , OH, and H2O. Chemical composition of tatarinovite (wt %; ICP-AES; H2O and CO2 determined by selective sorption of gaseous products of annealing) is: CaO 27.40, B2O3 4.06, A12O3 6.34, Fe2O3 0.03, SiO2 2.43, SO3 8.48, CO2 4.2, H2O 46.1, total 99.04. The empirical formula (calculated on the basis of 3 Ca apfu) is: H31.41Ca3.00(Al0.76Si0.25)∑1.01(B0.72S0.65C0.59)∑1.96O24.55. Tatarinovite is hexagonal, space group P63, a = 11.1110(4) Å, c = 10.6294(6) Å, V = 1136.44(9) Å3, Z = 2. Its crystal-chemical formula is: Ca3(Àl0.70Si0.30)  {[SO4]0.34[B(OH)4]0.33[CO3]0.24}{[SO4]0.30[B(OH)4]0.34[CO3]0.30[B(OH)3]0.06}(OH573O0.27)・12H2O. The strongest reflections of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 9.63 (100) (100), 5.556 (30) (110), 4.654 (14) (102), 3.841 (21) (112), 3.441 (12) (211), 2.746 (10) (302), 2.538 (12) (213). Tatarinovite was named in memory of the Russian geologist and petrologist Pavel Mikhailovich Tatarinov (1895—1976), a well-known specialist in deposits of chrysotile asbestos. Type specimens are deposited in the Fersman Mineralogical Museum of the Russian Academy of Sciences, Moscow.

Key words: Tatarinovite, new mineral, ettringite group, boron, rhodingite, Bazhenovskoe deposit, the Middle Urals.