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 30
Fig. 8. Fig., 4. has twenty-four equal edges of 120°, and six tetragonal andeight trigonal angles. The principal axes join two oppositetetragonal angles.—Ex., garnet, boracite. 4. The tetrakishexahedrons (variety of icositetrahedron,fig. 4) are bounded by twenty-four isosceles triangles, ar-ranged…
Precious stones · Building stones · Mineralogy
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