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Identity Helpstrange twinning & habit of Durham fluorite
25th May 2007 02:55 UTCTony Peterson Expert
I'm used to seeing crystals with modified habit, as a result of impurities selectively adhering to one set of faces, slowing their growth, and thereby making them larger. However, this doesn't need to involve a change in symmetry. But here, the flattening of the fluorite cubes (along <001>, I presume) seems to involve a reduction in symmetry (to tetragonal, it would seem). My next post on this thread shows another type of twinning which could only occur if <001> has been differentiated from <100> and <010>.
Can anyone enlighten me? Has a structural determination been made of this tabular fluorite? What is the origin of this change in habit, if not symmetry?
Tony
25th May 2007 03:01 UTCTony Peterson Expert
If I had proper microscopic equipment, rather than just a ring extender for my macro, I could get better shots and I may try to image these stacks parallel to <001>. Comments? Am I seeing things?
Tony
25th May 2007 10:32 UTCSpencer I. Mather
25th May 2007 11:55 UTCPeter Haas
25th May 2007 13:19 UTCTony Peterson Expert
Tony
25th May 2007 13:48 UTCFerdinando Giovine
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