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 75
re parallel to each other, and conse-quently the principal axis is also the twin axis. Usuallythe two individuals are united by a face parallel to the or-thodiagonal chief section, as in figure 89 of gypsum, wheretwo crystals of the combination (ooPoo).ooP.—P, shownin fig. 59, unite so regularly…
Precious stones · Building stones · Mineralogy
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