oriented grain mounts
All,
Quite a few of our oriented mineral grain mounts are either showing their age (e.g., cracked epoxy or maybe Canada balsam, broken glass slides, etc.) or otherwise low in quality (e.g., having lots of cracks or veins or inclusions and yielding cloudy interference figures, not well-centered figures, etc.). I could go through a few iterations of cutting up some stuff from our mineral specimens, guessing at or doing rough measurements to find the orientations for various figures (Bxa, OA, etc.), sending them off for thin-sections....but before I do that, perhaps I should ask if anyone makes these anymore? If so, I'll bet they are expensive.
Kent
Dr. Kent Ratajeski
Lecturer and Dice Mineralogical Museum Director
North Hall 081
Department of Geology, Geography, and Environment
Calvin University
3201 Burton St. SE
Grand Rapids, MI 49546
(616) 526-6769
https://calvin.edu/directory/people/kent-ratajeski
Hi Kent,
The best way I've found is to use crushed and sieved pure mineral separates
prepared as grain mount thin sections. This approach does not incur
additional cost, allows multiple interference figure orientations within a
single thin section, eliminates the between mineral variability in
interference figure appearance due to birefringence, and engages the
student's problem solving skills in identifying grains suitable for the
desired interference figures.
Mike DePangher
Spectrum Petrographics Inc.
www.petrography.com
On Thu, Oct 17, 2024 at 6:57 AM Kent Ratajeski via MSA-talk <
msa-talk@minlists.org> wrote:
All,
Quite a few of our oriented mineral grain mounts are either showing their
age (e.g., cracked epoxy or maybe Canada balsam, broken glass slides, etc.)
or otherwise low in quality (e.g., having lots of cracks or veins or
inclusions and yielding cloudy interference figures, not well-centered
figures, etc.). I could go through a few iterations of cutting up some
stuff from our mineral specimens, guessing at or doing rough measurements
to find the orientations for various figures (Bxa, OA, etc.), sending them
off for thin-sections....but before I do that, perhaps I should ask if
anyone makes these anymore? If so, I'll bet they are expensive.
Kent
Dr. Kent Ratajeski
Lecturer and Dice Mineralogical Museum Director
North Hall 081
Department of Geology, Geography, and Environment
Calvin University
3201 Burton St. SE
Grand Rapids, MI 49546
(616) 526-6769
https://calvin.edu/directory/people/kent-ratajeski
MSA-talk mailing list -- msa-talk@minlists.org
To unsubscribe send an email to msa-talk-leave@minlists.org
At one time we got them from Wards but I don't know if they do that
anymore.
Jeff Walker
On Thu, Oct 17, 2024 at 9:52 AM Kent Ratajeski via MSA-talk <
msa-talk@minlists.org> wrote:
All,
Quite a few of our oriented mineral grain mounts are either showing their
age (e.g., cracked epoxy or maybe Canada balsam, broken glass slides, etc.)
or otherwise low in quality (e.g., having lots of cracks or veins or
inclusions and yielding cloudy interference figures, not well-centered
figures, etc.). I could go through a few iterations of cutting up some
stuff from our mineral specimens, guessing at or doing rough measurements
to find the orientations for various figures (Bxa, OA, etc.), sending them
off for thin-sections....but before I do that, perhaps I should ask if
anyone makes these anymore? If so, I'll bet they are expensive.
Kent
Dr. Kent Ratajeski
Lecturer and Dice Mineralogical Museum Director
North Hall 081
Department of Geology, Geography, and Environment
Calvin University
3201 Burton St. SE
Grand Rapids, MI 49546
(616) 526-6769
https://calvin.edu/directory/people/kent-ratajeski
MSA-talk mailing list -- msa-talk@minlists.org
To unsubscribe send an email to msa-talk-leave@minlists.org