Locality Madagascar
	Size 20 cm. accross
	Photographer D. Von Bargen
	Collection Seaman Museum
Labradorite, a member of the plagioclase feldspars will on occasion show flashes of colors generated by the diffraction of light by the different orientations of polysynthetic twinning domains in  the mineral grains. This variety of labradorite is also known by the gem term "spectrolite". Most examples of this phenomenon are less striking than shown by this specimen.