CHAPTER III. Turquoise. TURQUOISE is a hydrated phosphate of alumina sometimes containing small quantities of copper, iron, or manganese. Its hardness is 6, and specific gravity 2.75. The finest varieties,
Continue reading »DIAMOND CUTTING AND POLISHING IT has been shown in the opening chapter of this work that fancy has still, and probably must forever have, a free range for its surmise
Continue reading »Chapter 14: HOW TO MAKE SYNTHETIC DIAMONDS CARBON IS ONE OF THE MOST INTERESTING of all the ninety-two elements, because of the many forms in which the pure element is
Continue reading »PART II “PEASANT” JEWELLERY—BARBARIC JEWELLERY—MYCENAEAN PERIOD—ETRUSCAN PERIOD—GREEK WORK-ROMAN OSTENTATION — ROMAN EXTRAVAGANCE — ROMAN WORK—ALEXANDRIAN WORK—THE TREASURE OF HILDESHEIM—THE TREASURE OF BERNAY—THE TREASURE OF BOSCOREALE—THE TREASURE OF PETROSSA—BYZANTINE ART—THE PALA
Continue reading »DIAMOND CUTTING The Diamond, the hardest of all known bodies, can only be manipulated by means of powdered Diamond. This powder is prepared generally from bort, or faulty Diamonds, and
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