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FIRE IN THE EARTH
In this case the corresponding rough or slightly touched areas will appear at the opposite corners of an imaginary square. If the "mass" has been sawn, the grain runs across the marks on the table surface, but all polishing is done across the grain.
After identifying the character of the "mass" of the stone, the polisher goes ahead with his polishing or faceting—and it is here that the word "grinding" is more appropriate than in connection with rounding. Anyhow, he works on the soft corners, four "templets" above and the corresponding four pavilions below, to form a cross. Then he superimposes upon the cross, above or below, a companion set of templets or pavilions. On the top of the stone the facets are com­pleted in sets of three, a "star" and a pair of "skill-facets" nearest to it. Similarly on the bottom each pair of con­tiguous "skill-facets" are worked together. Always the direc­tion of the grain is important!
In other words (that technical expert was lurking behind the above paragraph again), the diamond is turned so that the face to be ground is at the correct angle, is pressed on the wheel by hand or with lead weights, until the facet is flat, smooth, and perfect. Forty to fifty times the solder must be melted, or the prongs loosened, and the stone reset at a new angle. Each time the whining, shrill noise of the wheel must start again before the brilliant is finished. Cutting a one-carat stone thus takes from three days to a week; larger stones, proportionately longer.
When the stone is finished, it weighs about half what it did as a sawn or split "rough." But it is no longer the filmy, salt-looking thing we beheld in the beginning. It is a brilliantly faceted thing of beauty, shining with ever-changing colors of the rainbow, a triumph of cold fire that came from the center of the earth.
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