This has the BEST bubble of ANY of the Petrol included Quartzes I've sold over the last 10 years! It is actually a four phase inclusion in a single terminated Quartz crystal found in central Pakistan 4 years ago. It is highly fluorescent under both short wave and long wave (LW pictured). There are at least 2 moving bubbles, Each with specks of carbon that move within the fluid chambers. The gas bubble forms when the the Quartz cools after forming, the petroleum contracts more than the Quartz because it is less dense, it pulls a vacume within the fluid thus creating a "gas" bubble.  The four phases are: the gas bubble trapped in the petroleum, the petroleum itself, a darker brown previously organic material, and black carbon inclusions. I learned this from an insightful geologist who specializes in Quartz inclusions, whom I met at the Tucson Main show. This crystal has an attractive gold and brown color range. 

I am included a 60 power hand microscope for FREE with this purchase! It has both regular and long wave LEDS to look at this amazing crystal. (a $14.95 value)