Hartite from Bílina

• Published in: The American mineralogist 1998-12, Vol.83 (12), p.1340-1346
• Main Authors: Bouška, Vladimír, Císařová, Ivana, Skála, Roman, Dvořák, Zdenĕk, Zelinka, Jaroslav, Žák, Karel
• Format: Article
• Language: English
• ISSN: 0003-004X; 1945-3027
• DOI: 10.2138/am-1998-1224

In the Bílina Mine (Czech Republic), a very chemically pure material corresponding to hartite was found as a product of distillation into the pelosiderite nodule during coalification of a lignite seam in the Miocene or later. The amount of the material available allowed characterizing this natural mineral equivalent of the hydrocarbon (1)-phyllocladane [16α(H)-phyllocladane] thoroughly. Elementary analysis of hartite from Bílina gave C = 87.45 wt% and H = 12.55 wt%, which corresponds to the formula C . The IR spectrum demonstrated the presence of gem-dimethyl groups (doublet δ CH at 1369 and 1383 cm ). Other bands indicated the presence of methyl and methylene groups. NMR studies showed that the hydrocarbon (hartite) molecule contains four CH groups, nine CH groups, four CH groups, and three quaternary carbon atoms. The sample exhibits a well-defined melting point between 71 and 71.5 °C. Measurements of optical rotation gave [α] = 124.28 (CHCl , c = 0.7). Lattice parameters from single-crystal study measured at 293(2) K were a = 11.407 (1), b = 20.952 (2), c = 7.4060 (8) Å, α = 93.941 (9)8, β = 100.750 (8)°, and γ = 80.499 (9)°. The crystal system is triclinic with space group Pl, Z = 4, V = 1713.8 (3) Å . Densities are D = 1.04 g/cm and D = 1.064 g/cm , respectively. Isotopic composition of C in hartite from Bı´lina gave δ = - 24.4(1) ‰, a common value for coal and organic sedimentary material derived from higher plants.