Three videos of yoderite [Mg(Al,Fe)3(SiO4)2O(OH] in thin section, showing typical textures and optical characteristics. Supported by Boise State University and the US National Science Foundation.
Key characteristics: High relief, spectacular blue-lavender-yellow pleochroism, moderate interference colors
00:00 Prof. Roberta Rudnick sent me this rock
00:31 Different pleochroism
01:01 Just spectacular!
