The possible topologic structure types of orthopyroxene with space group P21ca comprise four kinds of tetrahedral chains and four kinds of octahedral sites.all
Argentian mercurian gold,golden-yellow in colour,is a variety of native gold containing Ag and Hg,coccurring as hexagonal and tetragonal crystals in hairy,milk-
Based on the data developed from various s natural waters in the Qinghai Lake area and ostracode shells present in drill core QH-16A of recent lake-floor sedime