Metamorphism of the skarn rocks from the Sasa ore field

The aim of this paper is to define the metamorphism of the skarn rocks from the Sasa ore filed. In these rocks ilvaite, rhodonite, bustamite, johansenite-ferrojohansenite, andradite, actinolite-ferroactinolite and epidote were determined. On the base of the presence minerals associations in studied rocks were determinated three facies: albite-epidote-hornfels facies; hornblende-hornfels facies; K-feldspate-cordierite-hornfels facies. The rocks studied are formed in temperature condition T 400–800oC and preassure P 1.5–2 kbar

Metamorphism of the Skarn Rocks from the Sasa Ore Field

The aim of this paper is to define the metamorphism of the skarn rocks from the Sasa ore filed. Inthese rocks ilvaite, rhodonite, bustamite, johansenite-ferrojohansenite, andradite, actinolite-ferroactinolite and epidotewere determined. On the base of the presence minerals associations in studied rocks were determinated three facies:albite-epidote-hornfels facies; hornblende-hornfels facies; K-feldspate-cordierite-hornfels facies. The rocks studiedare formed in temperature condition T 400–800oC and preassure P 1.5–2 kbar

Lithio­marsturite, LiCa2Mn2Si5O14(OH)

Lithio­marsturite, ideally LiCa2Mn2Si5O14(OH), is a member of the pectolite–pyroxene series of pyroxenoids (hydro­pyroxenoids) and belongs to the rhodonite group. A previous structure determination of this mineral based on triclinic symmetry in space group P by Peacor et al. [Am. Mineral. (1990), 75, 409–414] converged with R = 0.18 without reporting any information on atomic coordinates and displacement param­eters. The current study redetermines its structure from a natural specimen from the type locality (Foote mine, North Carolina) based on single-crystal X-ray diffraction data. The crystal structure of lithio­marsturite is characterized by ribbons of edge-sharing CaO6 and two types of MnO6 octa­hedra as well as chains of corner-sharing SiO4 tetra­hedra, both extending along [110]. The octa­hedral ribbons are inter­connected by the rather irregular CaO8 and LiO6 polyhedra through sharing corners and edges, forming layers parallel to (1), which are linked together by the silicate chains. Whereas the coordination environments of the Mn and Li cations can be compared to those of the corresponding cations in nambulite, the bonding situations of the Ca cations are more similar to those in babingtonite. In contrast to the hydrogen-bonding scheme in babingtonite, which has one O atom as the hydrogen-bond donor and a second O atom as the hydrogen-bond acceptor, our study shows that the situation is reversed in lithio­marsturite for the same two O atoms, as a consequence of the differences in the bonding environments around O atoms in the two minerals

Nonmetallic skarn minerals of the Sasa ore field

The paper presents the mineralogical characteristics of the non-metallic skarn minerals of the Sasa ore field. The analyses were carried out in the Institute for Crystallography in Zurich and the laboratories of the Faculty of Mining and Geology in Stip