I noticed that for uploading thin section photographs, two options are listed: (1) thin section (normal light), and (2) thin section (polarized light). Although I can understand that some thin sections might simply be photographed the way mineral specimens are (hence the "normal light" option), I suspect generally thin sections are viewed and photographed through a petrographic microscope. Hence, I would suggest that the "polarized light" option be eliminated and replaced by two more informative options, one for "thin section (plane polarized light, PPL)" and one for "thin section (crossed polars, XPL)". A similar distinction should be made for photomicrographs of polished blocks in reflected light as well. As petrographers begin to upload more and more photos of minerals in thin section and polished blocks (particularly those confirmed by microprobe and/or micro-Raman), mindat can become an important visual resource for the optical properties of rare minerals. Thanks. http://www.mindat.org/forum.php?read,7,252939,252939#msg-252939 Thu, 23 May 2013 02:52:49 +0000 Phorum 5.2.15a http://www.mindat.org/forum.php?read,7,252939,253040#msg-253040 http://www.mindat.org/forum.php?read,7,252939,253040#msg-253040 Frank K. Mazdab Mistakes and Errors Wed, 22 Feb 2012 02:32:21 +0000 http://www.mindat.org/forum.php?read,7,252939,252951#msg-252951 http://www.mindat.org/forum.php?read,7,252939,252951#msg-252951 Ralph Bottrill Mistakes and Errors Tue, 21 Feb 2012 11:10:00 +0000 http://www.mindat.org/forum.php?read,7,252939,252948#msg-252948 http://www.mindat.org/forum.php?read,7,252939,252948#msg-252948 Uwe Kolitsch Mistakes and Errors Tue, 21 Feb 2012 10:47:03 +0000 http://www.mindat.org/forum.php?read,7,252939,252946#msg-252946 http://www.mindat.org/forum.php?read,7,252939,252946#msg-252946
you are right that thin sections photographed in PPL vs. "normal light" usually look different and have to interpreted differently, so we should think about better categories here.

But we should watch out that we do not end up with categories like "PPL with filter", "XPL with compensator", etc.
It might be simpler to leave it up to the photographer to add the necessary info to the photo description and just lump all the different thin section photos in a single category.]]> Amir C. Akhavan Mistakes and Errors Tue, 21 Feb 2012 10:05:24 +0000 http://www.mindat.org/forum.php?read,7,252939,252939#msg-252939 http://www.mindat.org/forum.php?read,7,252939,252939#msg-252939
As petrographers begin to upload more and more photos of minerals in thin section and polished blocks (particularly those confirmed by microprobe and/or micro-Raman), mindat can become an important visual resource for the optical properties of rare minerals.

Thanks.]]> Frank K. Mazdab Mistakes and Errors Tue, 21 Feb 2012 07:27:37 +0000