Geometrical and Optical Properties, and Crystal Structure of Tenorite

Abstract

Part I. Geometrical and Optical Properties.The goniometrical measurements of N. Story-Maskelyne 1 ) on crystals of tenorite (also called melaconite) found with cuprite and chrysocolla in a chloritic veinstone from Lostwithiel, Cornwall, satisfy the symmetry requirements of the monoclinic system, and the crystal habit illustrated in the drawing of Story-Maskelyne is clearly that of the holohedral class of the monoclinic system. Moreover, as A. Scacchi 2 ) has pointed out, the goniometrical measurements of J. Jenzsch 3 ) on artificial crystals of cupric oxide formed near a flue in a smelterhearth during roasting of copper matte with sodium chloride at Freiberg, yield calculated elements agreeing with those of Story-Maskelyne, and the crystals drawn by Jenzsch exhibited the same habit and twinlaw as those of Story-Maskelyne. Jenzsch interpreted his crystals as orthorhombic but his measurements do not satisfy orthorhombic symmetry requirements either qualitatively or quantitatively.Numerous inconsistencies and errors in detail occur in the papers of Story-Maskelyne, of Jenzsch, and of Scacchi. For this reason we have carried out geometrical and optical, as well as X-ray measurements, sufficient to establish our conclusions without the use of previous experimental results. At the same time our conclusions are in agreement with previously reported experimental facts. Our conclusions rest on optical, geometrical, and X-ray study of the thin natural tenorite crystals deposited on the lavas of Mount Vesuvius, on X-ray study of chemically pure artificial cupric oxide powder, and finally on geometrical and X-ray study of single faceted crystals of tenorite prepared for the purpose by recrystallization in molten sodium hydroxide. 1) Verh. Petersb. Min. Ges. 1 (1866) 147. 2) Contribuzioni mineralogiche per aervire alia storia dell'incendio vesuviano del mese di Aprile

X-ray structural investigations of gold compounds

“…This is, however, a considerable oversimplification; as was remarked in the original publications (7,8) there are several short (320 pm) Au-Te contacts for each gold atom.…”

The morphology of calaverite (AuTe2) from data of 1931. Solution of an old problem of rational indices

“…The first Weissenberg photographs made by Tunell & Ksanda (1935) confirmed the monoclinic (sylvanite-like) lattice as the basic structural one. Excluding any orthorhombic groups, they proposed the C2/m space group.…”

“…Excluding any orthorhombic groups, they proposed the C2/m space group. In a subsequent paper (Tunell & Ksanda, 1936) the morphological unit cell was established. Also, extra so-called 'adventive' diffraction spots were observed, which could not be ascribed to planes of the structural lattice, unless the monoclinic unit cell was enormously expanded.…”

The Close Relationships between the Crystal Structures of MO and MSO4 (M = Group 10, 11, or 12 Metal), and the Predicted Structures of AuO and PtSO4

“…However, among the LTM monoxides, only CdO is known to take up the ideal rock salt structure under ambient (p, T) conditions, whereas the remaining LTM monoxides MO (M = Pd, Pt, Cu, Ag, Zn, Hg) all crystallize in different crystallographic systems (Table 1; for cell parameters see Table S2, Supporting Information). The known transition metal monosulfates are limited to 3d (groups [7][8][9][10][11][12] and LTM 4d (M = Pd, Ag, Cd) and 5d (M = Pt, Hg) monosulfates, and none of them crystallize in a rock salt type structure. Similarly, as in the case of 3d monoxides, the 3d metal monosulfates adopt the same crystal structure types, orthorhombic Cmcm (CrVO 4 -type) and/or Pnma (CuSO 4 -type) cell (Z = 4), whereas again the LTM monosulfates all crystallize in distinct space groups (Table 1; for cell parameters see Table S2, Supporting Information).…”