Introduction: More than 80 fossil meteorites have been found in a ~4 m quarry layer of mid-Ordovician limestone in Sweden [1, 2]. Their cosmic-ray exposure (CRE) ages correlate inversely with sediment deposi-tion age and indicate very rapid (<1.2 Myrs) transport from the asteroid belt [3]. The same layer contains up to 3 sediment-dispersed, extraterrestrial chromite (SEC) grains (>63 µm) per kg...

The production of ferrochrome alloy from chromium bearing chromite ores is conducted at high temperature under highly reducing conditions. However, albeit completely unintended, it is impossible to completely exclude oxygen from all high temperature process steps, with the corresponding possibility arising for the generation of small amounts of Cr(VI) species. Certain Cr(VI) species are regarde...

Electron-probe microanalyses and scanning electron microscopy of chrornitites from some ultramafic members of Neyriz ophiolite indicate that sulifides of platinum- group minerals (PGMs) occur as solid inclusions in chromite grains. Laurite with the general formula of (Ru ,Os ,lr ) S , and erlichmanite are the main identified sulfide phases. The PGMs occur as 4 to 20 microns euhedral to rect...

-Cr(III) and Cr(VI) compounds of varying solubilities have been tested in vitro for their ability to inhibit cell growth and nucleic acid and protein syntheses in BHK cells, to induce alterations in the mitotic cycle in HEp cells, and to increase the frequency of chromosomal aberrations and sister chromatid exchanges (SCE) in CHO cells. All Cr(VI) compounds, and particularly those containing so...