RAVATITE, C14H10, A NEW ORGANIC MINERAL SPECIES FROM RAVAT, TAJIKISTAN

The new organic mineral ravatite (analyzed as C14.1H9.9, idealized for mula C14H10), identical with synthetic phenanthrene, is described as a sublimation product caused by the natural combustion of a brown coal seam near Ravat/Tadzhikistan (southwestern Tjan' Shan'). It forms thin , platelet-like individuals with diameters of mainly a few hundred mic rometers which are usually aggregated to thin crusts on a bituminous, H2SO4-impregnated coaly-earthy material. Ravatite is colourless, or - dependent on the amount of coaly, gas and other inclusions - white to pale grey and transparent to translucent. It shows a vitreous to wax-l ike lustre. Ravatite has a monoclinic lattice (space group P2(1)) with a(o) = 8.392(5)angstrom; b(o) = 6.181(3)angstrom; c(o) = 9.558(5)angs trom; beta = 98.48(12)-degrees; V = 490.4(4)angstrom3; Z = 2. The obse rved strongest five X-ray powder diffraction lines [d in angstrom (I(r el)) (hkl)] are: 9.434(100)(001); 4.028(13)(201BAR); 4.94](11)(110); 4 .724(11)(002); 3.371(10)(211BAR). The Mohs hardness is about 1; the ca lculated and the measured densities are 1.207(1) and 1.11(2) g/CM3, re spectively. Ravatite shows a whitish-yellow fluorescence under ultravi olet light. The initial temperature of melting is 94.3-degrees-C. Infr ared absorption and Raman data do not differ significantly from data o f synthetic phenanthrene.