Dyed and Filled Sillimanite as Ruby Imitation

Recently, some samples claimed to be rubies from Kashmir were sent to testing center.However,there was a sillimanite sample,which was dyed and filled.The refractive index of the sample is 1.65.Under ultraviolet fluorescent lamp,the sample shows orange by SW,and red by LW.By gem microscope,the local gloss of surface is quite weak and interior shows fibrous structure and a small amount of bubbles.A group of cleavage can be seen at the bottom of the sample.The infrared spectrum result shows the sample is sillimanite.The dyed and filled sillimanite deserves attention in routing inspection.