INTERESTING INCLUSIONS IN QUARTZ CRYSTAL
Taywiga Phataphol B.Sc., G.G.
Recently, we have received the special quartz crystal from Mr. Anwar Afghan. This quartz weight 21.53 cts. and has a double terminated crystal shape. It was said to originate from Himalaya Mountain in Pakistan-Afghanistan area.
Figure 1: 21.53 cts. Double Terminated Quartz Crystal
Figure 2: 21.53 cts. Double Terminated Quartz Crystal
When testing the stone, the properties were the followings; RI = 1.54 - 1.55, SG = 2.62, which are the normal properties of quartz. What attracted our attention was the interesting yellow inclusion contains gas bubble and black spot material. When tilting the stone, the gas bubble was moving. Microscopic examination using 10- 45 times magnification revealed many of these yellow fluid filled pockets and all of them contain free moving gas bubble. Under long-wave ultraviolet radiation, the yellow fluid inclusion glow a distinctive blue color.
Figure 3: Petroleum inclusion contains free moving gas bubble
Figure 4: Blue fluorescence under long-wave ultraviolet radiatio
According to the UV fluorescence, it indicated that the yellow fluid inclusion is petroleum oil. In addition, the black spot inclusion is possibly a bituminous material.
E.J. Gubelin, J.I. Koivula Photoatlas of Inclusions in Gemstones Volume 2, p 576.