A
quartzose calc-schist with magnetite from the Precambrian of west
Texas (color, 378Kb). Quartz is red, calcite is blue, magnetites
are black with spots, talc is black. Sample courtesy of S. Grimes
more
of the same sample (color, 536Kb)
and
still more (color, 410Kb)
A
pelitic schist from the Llano Uplift, Central Texas (color, 630Kb)
Quartz is red, plagioclase is dark blue, sillimanite is light
blue, haven't checked what the green is yet but it may be epoxy.
Black areas are biotite and/or garnet.
Another
pelitic schist from the Llano Uplift (color, 473Kb) Quartz is
red, plagioclase is blue.
Luminescence
haloes can also be seen in the quartz (red) around the garnets
(black) in this strange garnetiferous rock from the Park Range
of Colorado (color, 252Kb). Bright blue grains are microcline
feldspar, dark blue grains in the lower right corner are calcite
or dolomite. Sample courtesy of J. Rougvie.
A
microfracture in a strange garnet-quartz-carbonate-microcline
rock from the Park Range of Colorado (color, 264 Kb). Bright blue
grains are microcline feldspar, red grains are quartz, black grains
are mostly garnet. SEI image of this same area shows fracture
in microcline is filled, fracture in quartz is partially-filled.
Sample courtesy of J. Rougvie.
A
production of:
Robert M. Reed
Department of Geological
Sciences
University
of Texas at Austin
rmr@uts.cc.utexas.edu