Geometric Forms
As illustrated in the entry on granophyre, crystals of quartz and feldspar can crystallize in intricate intergrowths with geometric forms, sufficiently coarse to be easily distinguishable by means of the microscope. Often the quartz or the feldspar of the intergrowth extinguishes simultaneously with a crystal of either of these minerals lying in the center of the aggregate. These intergrowths crystallize from a melt, not in the solid state.
Read more about this topic: Spherulite
Famous quotes containing the words geometric and/or forms:
“New York ... is a city of geometric heights, a petrified desert of grids and lattices, an inferno of greenish abstraction under a flat sky, a real Metropolis from which man is absent by his very accumulation.”
—Roland Barthes (1915–1980)
“It is not however, adulthood itself, but parenthood that forms the glass shroud of memory. For there is an interesting quirk in the memory of women. At 30, women see their adolescence quite clearly. At 30 a woman’s adolescence remains a facet fitting into her current self.... At 40, however, memories of adolescence are blurred. Women of this age look much more to their earlier childhood for memories of themselves and of their mothers. This links up to her typical parenting phase.”
—Terri Apter (20th century)