Verrill, A. Hyatt (Alpheus Hyatt), 1871-1954 · New York, R. M. McBride & co. · leaf 52
it is possible to do so, gems and semi-precious stones should be shown in both the cut and ROCKS AND MINERALS 31 uncut state. The majority of mineral and rockspecimens may be displayed in open trays, cases, orcabinets, but some varieties show to better advan-tage when set off by special… … Fig. 5. Calcite crystals have the peculiar property of causing allthings to appear double when seen through the mineral cite has the peculiar property of producing doublerefraction. That is, a line, letter, or other markseen through a transparent piece of calcite appearsdouble and specimens of this…
Collectors and collecting
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
