Clay Films From Coffee Pot

This is a sample of a clay film that formed in a pot of coffee. The film tended to float to the surface and lay flat at the interface of the water and the air. The flakes were lifted by touching a microscope slide to the interface. The film with some coffee lifted free from the coffee, was allowed to dry and was then mounted in resin with a refractive index of 1.515. The crystals are from the coffee and are not part of the film.