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SummaryOnoratoite, a new antimony oxychloride Sb8O11Cl2 from the antimony mines of Cetine di Cotorniano, Rosia (Siena, Italy), is triclinic with lattice constants a 18·92, b 4·03, c 10·31 Å, α ≃ γ ≃ 90°, β 110°. Density 5·3 meas., 5·49 calc. The needle-like crystals are elongated on [010] and show as prominent form {001}. Other forms present are {100}, {201}, {401}, {412}.The new mineral is optically biaxial negative, extinction angle small and variable from 0° to 14°. Orientation β:[100] ca. 8°; α:[001] ca. 12°; γ:[010] 0 to 14°. Refractive indices are 2·26 > γ > 2·23, 2·23 > β > 2·18. Birefringence γ-β 0·024 (meas.).The stability field of onoratoite has been investigated by systematic thermo-gravimetric and differential thermal analysis of antimony oxychlorides and by a direct study of equilibrium relationships in the system SbCl3-Sb2O3-HCl-H2O. The probable mechanism of formation of onoratoite is discussed.Onoratoite is named in honour of the Italian mineralogist Ettore Onorato.

S An unusual occurrence of huntite CaMg3(CO3)4, found in a wooden box pertaining to the cargo of a sunken Roman ship of imperial age in the Golfo di Procchio on the north coast of Elba is described. The huntite has been identified on the basis of chemical analysis, thermo‐gravimetric analysis, differential thermal analysis, X‐ray diffraction and electron microscope images. Having ruled out its origin by the reaction of sea water on some pre‐existing material it is concluded that the huntite represented the original content of the box. The origin and the provenance of huntite and its possible use are discussed.

The AA. illustrate the results of the analyses, by fluorescence X-ray and refractive index, of obsidians both from source areas of central and eastern Anatolia and from late-chalcolithic levels of Arslantepe (Malatya, Turkey). These levels are characterized by a large prevalence of eastern obsidians from many source areas; therefore their evidence fit in the pattern of diffusion outlined for the Chalcolithic by previous authors.

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