Introduction: Igneous and metamorphic rocks commonly contain a mineral assemblage that allows oxygen fugacity to be calculated or constrained such as FeTi oxides, olivine-opx-spinel, or some other oxybarometer [1]. Some rocks, however, contain a limited mineral assemblage and do not provide constraints on fO2 using mineral equilibria. Good examples of the latter are orthopyroxenites or dunites,...

MINERALOGICAL and physical characteristics of natural chromites from Oman ophiolites have been recently investigated using M6ssbauer spectrocopy (MS), X-ray diffraction (XRD) and Scanning electron microscopy (SEM) by Al-Alawi et al. (1996). From the MS analysis together with the SEM data, they derived the chemical formula for specimens collected from two separate chromite deposits named Tawiyah...

In this study we attempt to distinguish the relationship between the altered chromites and non-altered ones by X-ray diffraction. For the purpose of this study, an assemblage of altered/non-altered and deformed/non-deformed ophiolitic chromites has been collected and analyzied. Sharp and doubled peaks are resulted from non-altered and altered samples respectively. By using XRD studies, the...

Petrography: The interior of the stone consists of relatively small (mean grain size 1.6 mm), angular olivine grains (~73 vol%) in an iron metal matrix (Fig. 1). Ferric oxides are abundant. Samples easily fragment because of the weathering and numerous, probably preterrestrial, fractures. Olivine contains numerous small (typically 50 μm diameter) inclusions, visible in the SEM, that consist of ...

Investigation of parent magma evolution and origin chromites in Cheshmeh-Bid, ophiolite Neyriz, Fars