Purity = supposedly pure, but have seen minute particles of gold under the microscope @ 40x when being digested in a 50/50 solution of Nitric acid/water.
Image taken with 35mm camera and a 135mm lens, set at macro for close-up focusing, shutter speed = 1/250th of second in bright sun using 200 film and developed by Kodak 1 hour commercial labs and then digitized.
There are no sublimates close to the ball of Mercury, but as the picture indicates a blackish sublimate formed well away from source of heat that was directed at this ball of mercury. This blackish sublimate is actually extremely small beads of mercury easily visible at 20x.
After a week practically none of this blackish looking sublimate was left, only an occasional tiny ball of mercury indicating that room temperature volatilized this finely divided mercury.

Image created with B&L SZ5 microscope @ 40 power, coupled to a ccd camera and computer.
No Sublimates close to this liquid mercury.
The cracks in plaster tablet are due to heat from propane torch.
The carved out depression is to help keep the metal in confined area due to blast from applied torch flame.