Interference patterns These shimmering colours were snapped through a microscope on the surface of a platy inclusion within a pink spinel crystal from Burma. The lighting is a side mounted fibre optic lamp combined with darkfield, in which the light is diffused from the side into the bottom of the gem. The colours are caused by reflections off cleavage planes within the inclusion, called thin film interference. The image is about a millimetre across. Loz Image credit: Loz
















