Abramovite, a new mineral species, has been found as fumarole crust on the Kudryavy volcano, Iturup Island, Kuriles, Russia.
The mineral is associated with pyrrhotite, pyrite, würtzite, galena, halite, sylvite, and anhydrite. Abramovite occurs as
tiny elongated lamellar crystals up to 1 mm long and 0.2 mm wide (average 300 × 50 μ m), which make up chaotic intergrowths
in the narrow zone of fumarole crust formed at ∼600°C. Most crystals are slightly striated along the elongation. The new mineral
is silver gray, with a metallic luster and black streak. Under reflected light, abramovite is white with a yellowish gray
hue. It has weak bireflectance; anisotropy is distinct without color effects. The chemical composition (electron microprobe)
is as follows, wt %: 20.66 S, 0.98 Se, 0.01 Cu, 0.03 Cd, 11.40 In, 12.11 Sn, 37.11 Pb, 17.30 Bi; the total is 99.60. The empirical
formula calculated on the basis of 12 atoms is Pb
1.92Sn
1.09In
1.06Bi
0.89(S
6.90Se
0.13)
7.03. The simplified formula is Pb
2SnInBiS
7. The strongest eight lines in the X-ray powder pattern [
d, Å (
I)(
hkl)] are 5.90(36)(100), 3.90(100)(111), 3.84(71)(112), 3.166(26)(114), 2.921(33)(115), 2.902(16)(200), 2.329(15)(214), 2.186(18)(125).
The selected area electron diffraction (SAED) patterns of abramovite are quite similar to those of the homologous cylindrite
series minerals. The new mineral is characterized by noncommensurate structure composed of regularly alternated pseudotetragonal
and pseudohexagonal sheets. The structure parameters determined from the SAED patterns and X-ray powder diffraction data for
pseudotetragonal subcell are:
a = 23.4(3),
b = 5.77(2),
c = 5.83(1) Å, α = 89.1(5) °, β = 89.9(7)°, γ = 91.5(7)°,
V = 790(8) Å
3; for pseudohexagonal subcell:
a = 23.6(3),
b = 3.6(1),
c = 6.2(1) Å, α = 91(2)°, β = 92(1)°, γ = 90(2)°,
V = 532(10) Å
3. Abramovite is triclinic, space group P(1). The new mineral is named in honor of Russian mineralogist Dmitry Abramov. The
type material of abramovite has been deposited in the Fersman Mineralogical Museum, Russian Academy of Sciences, Moscow.
Considered by the Commission on New Minerals and Mineral Names, Russian Mineralogical Society, February 14, 2006. Approved
by the Commission on New Minerals and Mineral Names, International Mineralogical Association, June 30, 2006 (IMA no. 2006-016).
Original Russian Text © M.A. Yudovskaya, N.V. Trubkin, E.V. Koporulina, D.I. Belakovsky, A.V. Mokhov, M.V. Kuznetsova, T.I.
Golovanova, 2007, published in Zapiski Rossiiskogo Mineralogicheskogo Obshchestva, 2007, Pt CXXXVI, No. 5, pp. 37–43.