Microphotography, in plane polarised light, of kyanite (Ky). A crystal shows the 2 characteristic sub-orthogonal cleavage planes. These are not visible on the second crystal, because this one has a different orientation with respect to the structure of the mineral. Muscovite (musc) and quartz (Q) are also present in this metapelite. Kyanite is also called cyanite .The long side of the photo is about 1 mm.
Kyanite (Ky) under crossed-polarised light. A crystal shows partial extinction because it has been deformed. Note the bright colours of the muscovites. The quartz is white to black.
Back to the PhotoGallery, to the Metamorphism Course or else to the Home Page ?