A popular treatise on gems, in reference to their scientific value; a guide for the teacher of natural sciences, the jeweller, and amateur: together with a description of the elements of mineralogy, and all ornamental and architectural materials .. (1859)
Feuchtwanger, Lewis. [from old catalog] · New York, D. Appleton & company · leaf 93
s, or fluid;but some crystals produce a still more remarkable result.The ray of light which entered them as one is divided intotwo rays, each following different angles, or is doubly re-fracted. In minerals of the tesseral system this propertydoes not exist, but it has been always observed in… … Fig. 95. crystals of calc-spar, especially in the beautiful transparentvariety from Iceland, in which it was first observed anddescribed by Erasmus Bartholin in a work published atCopenhagen in 1669. The subjoined figure will illustrate this singular proper-ty. It represents arhomb of Icelandsjjar,…
Precious stones · Building stones · Mineralogy
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
