Although cubic in form, analcite usually shows feeble doublerefraction, and is thus optically anomalous.
2
Histological examination showed typical amyloid masses that demonstrated apple-green doublerefraction on examination of the Congo red-stained section under polarized light.
3
The difference, 0.1723, between these two indices gives a measure of the bi-refringence or doublerefraction.
4
Transparent and colourless, like glass, this mineral possesses the property of doublerefraction-anysmall object viewed through it in a particular direction appearing double.
5
Rays produced by the DoubleRefraction of Quartz.
6
Doublerefraction is displayed in a particularly impressive manner by Iceland spar, which is crystallized carbonate of lime.