AesrRAcr Oriented single crystals of marcasite have been inverted to pyrite by heating under vacuum in the temperature range 425 to 475″C. X-ray diffraclion studies reveal two preferred orientations of pyrite, with az of pyrite parallel to b of marcasite and or and os sub-parallel to [101] of marcasite, agreeing with the orientation of some natural inter-gronths of the two minerals. It is …
