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 41
ig. 20. Fig. 21. common predominant forms. In fig. 20 two tetrahedrons in opposite positions, — .•——, are combined. In fig. 21 a 2* 34 A PRACTICAL TREATISE ON GEMS. very comi^lex combination of seven forms is represented ina crystal of gray-copper ore, its full sign being— If {I) . coOoo (/) .…
Precious stones · Building stones · Mineralogy
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![An illustration from Cosmographia in qvatvor libros distribvta summo ordine, miraqve facilitate, ac breuitate ad magnam Ptolemæi mathematicam constructionem, ad vniuersamque astrologiam institutens. Francisco Barocio ... avtore. Cum præfatione eiusdem autoris, in qua perfecta quidem astrologiæ diuisio, & enarratio autorum illustrium, & voluminum ab eis conscriptorum in singulis astrologiæ partibus habetur: Joannis de Sacrobosco verò 84 errores, et alij permulti suorum expositorum, & sectatorum ostenduntur. rationibusq[uam] redarguuntur. Præcesserunt etiam quædam communia mathematica, necnon arithmetica, & geometrica principia, nonnullæq[uam] propositiones, de quibus in toto opere sæpe fit mentio: ac demum locupletissimus index eorum, quæ ipsa Cosmographia continentur .. (1585)](https://img.insideoutlibrary.com/img/200/ia-cosmographiainqv00baro-127-49.webp)
