Study on Gemmological and Mineral Characteristics of Phosphosiderite

Currently，there appears a kind of purple－red jade in Hong Kong market and the gemmological and mineral characteristics of this jade are researched by using conventional gemmological testing methods and FTIR，Raman spectrum，XRD and so on.The results show that the RI of the sample is 1.69～1.71，density is 2.50～2.62g/cm³，hardness is 4.FTIR and Raman spectrum researches show that the typical peaks result from ［PO₄］^3－ and crystal water H₂O and these features match with those of the phosphosiderite.The strong absorption peaks at 989，1 624，856cm^－1，and weak peaks in 100～500cm^－1 are the critical identification evidence of the jade sample.EPMA and XRD results show that the sample is phosphosiderite aggregate.And its mineral particles are short columnar and the sizes are between 10μm and 20μm.