Labradorite: Minfax

Name: Labradorite	Origin of name: named after Labrador, in Canada, where it is found.	Chemical composition: (Na,Ca)Al_1-2Si_3-2O₈
	Labradorite is a calcium-sodium plagioclase, an intermediate member of the plagioclase feldspar series, and an important constituent of certain igneous and metamorphic rocks (gabbros, norites and some gneisses). Schillerisation, or play of colours (pass your cursor over the picture to see what this is like), is a characteristic feature of labradorite. The iridescent blue and orange colurs are believed to be caused by reflection and refraction of light from microscopic cracks and inclusions on the cleavage planes.	Crystal system: triclinic
		Class: Silicates
		Hardness: 6.0-6.5
		Cleavage: perfect
		Colour: blue, grey, white or colourless
		Specific gravity: 2.69-2.72