The paper provides results of a detailed mineralogical study some chromitite ores from two deposits in the Southern Urals Kazakhstan: Almaz-Zhemchuzhina and Geofizicheskoe-VII. It is revealed that main ore minerals are Cr-spinel with high Cr# (Cr/(Cr + Al) = 0.8–0.83), as well serpentine chlorite, replacing primary olivine. Chromium spinel grains contain mineral inclusions, which distributed ra...

Mg-Fe2+ diffusion patterns in olivine and chromite are useful tools for the study of thermal history ultramafic massifs. In present contribution, we applied exponential modeling to geothermometry geospeedometry chromitite ores from two different ophiolite contexts. The Iballe (Northern Albania) hosts several pods within dunites. Primary re-equilibrated Mg#, estimated by using an function, provi...

The new mineral theophrastite, Ni(OH)2 , from Unst, is Mg-bearing and occurs associated with a very poorly crystalline Ni-containing mixed hydroxide of the pyroaurite type and/or zaratite on chromitite. X-ray powder diffraction data show a shift in d spacing toward brucite compared with pure Ni(OH)2. Infrared, thermal, chemical, optical, and physical data are presented together with indexed pow...

Alaskan-type complexes in British Columbia are potentially important hosts for economic concentrations of platinum-group elements (PGEs: Ruhlee, 1986; Evenchick er al.. IYXh) as well as other commodities such as chrome, nickel, cobalt, gold. jade and asbestos. To date, only the platinum-rich placers of the Tulameen complex have been exploited economically, yielding some 680 000 grams of impure ...