I have many specimens of prehnite from NJ and elsewhere. I have yellow, white, the usual green and some light blue. Does anyone know what causes the color variations in this mineral? Thanks. Gary http://www.mindat.org/forum.php?read,100,245413,245413#msg-245413 Sat, 18 May 2013 09:29:36 +0000 Phorum 5.2.15a http://www.mindat.org/forum.php?read,100,245413,245952#msg-245952 http://www.mindat.org/forum.php?read,100,245413,245952#msg-245952 Henry Barwood Analytical Techniques Sun, 18 Dec 2011 23:29:03 +0000 http://www.mindat.org/forum.php?read,100,245413,245420#msg-245420 http://www.mindat.org/forum.php?read,100,245413,245420#msg-245420 Hershel Friedman Analytical Techniques Thu, 15 Dec 2011 04:51:18 +0000 http://www.mindat.org/forum.php?read,100,245413,245415#msg-245415 http://www.mindat.org/forum.php?read,100,245413,245415#msg-245415 Warren Cummings Analytical Techniques Thu, 15 Dec 2011 02:51:02 +0000 http://www.mindat.org/forum.php?read,100,245413,245413#msg-245413 http://www.mindat.org/forum.php?read,100,245413,245413#msg-245413 gary moldovany Analytical Techniques Thu, 15 Dec 2011 01:34:59 +0000