“Whitening Phenomenon”of Quartzite Jade

In domestic jewelry market,some quartzite jade displays the"whitening phenomenon"with the appearance whitening and the transparency reducing.However,it is unclear in possible formation mechanism.In this article,the variations of apparent characteristics,internal texture and spectral signature were compared for the samples before and after the"whitening phenomenon".It was found that the"whitening phenomenon"occurred under daily condition was recoverable.Its emergence is mainly due to the loss of fillings,such as absorbed water,silicon oil and liquid paraffin,which can make the several-nanometer-wide micro fractures or large grain boundaries gradually emerge and cause light scattering.The"whitening phenomenon"could be more easily observed in the quartzite jade with loose structure and larger grain size.