A highly-zoned
zircon (grayscale, 126Kb, from Antarctica). The zoning is of a kind that
has been interpreted to be igneous in origin. The arcuate feature on the
left-center where zoning is missing suggests that the zircon was resorbed
at one point, probably while in a melt. The dark outer rim may be metamorphic
in origin. [The CL color of this zircon is a pale yellow, so the gray-scale
image was used] Antarctic zircons courtesy of M. Helper.
A bland,
but blue, zircon (color, 347Kb, also from Antarctica)
Metamorphic in origin?
Another
blue zircon, surrounded by red polishing grit (color, 189Kb, also from Antarctica).
The two dark fractures were induced during sample preparation.
A comparison of color
vs. grayscale images for a zoned zircon. (119 Kb of images)
A highly
zoned zircon (pale green), and several subtly zoned apatites (darker green)
from a schlieren in the Enchanted Rock Batholith of central Texas (color,
137 Kb). Sample courtesy of Doug Smith.
A production of:
Robert M. Reed
Department of Geological Sciences
University of Texas at Austin
rmr@uts.cc.utexas.edu