ten chromite ores from ophiolite complexes in se iran were analyzed mineralogically by xrd, chemically by xrf, and mineral chemistry by epma. the identified paragenesis of silicate minerals of chromite ores with the x-ray diffraction is pronounced differently. it consists of secondary phases formed as serpentine, cr-containing chlorite (kaemmererite), chromic garnet (uarovite) with preserved pa...

the compounds, lanthanium chromite, lanthanium magnetite and lanthanium ferric oxide were prepared through sol-gel methods in powdered form, then calcinated, peletized, and sintered at various temperatures. electrical conductivity of these compounds was measured at various temperatures. the effectiveness of strontium as a dopant on electrical conductivity was also investigated. electrical condu...

This paper describes unusual graphite–sulfide deposits in ultramafic rocks from the Serranı́a de Ronda (Spain) and Beni Bousera (Morocco). These deposits occur as veins, stockworks and irregular masses, ranging in size from some centimeters to a few meters in thickness. The primary mineral assemblage mainly consists of Fe–Ni–Cu sulfides (pyrrhotite, pentlandite, chalcopyrite and cubanite), graph...

Here we report the occurrence, chemistry, and U-Th-Pb isotopic systematics of three meteoritic zircon assemblages, two from the Vaca Muerta mesosiderite and one from the Simmern H5 chondrite. One of the Vaca Muerta zircons occurs in the mesosiderite proper, the other in a eucritic clast associated with chromite, ilmenite, and tridymite, whereas the Simmern zircon occurs in a chondrule composed ...