gem, ornamental mineral or organic substance: Diamond Cutting
In diamond cutting the stone is first cleaved or sawed to remove excrescences (outcroppings) or to break it into smaller stones. Cleaving is accomplished by making a groove in the surface in the direction of the grain, inserting a steel knife, and striking the back of the knife a sharp blow. The next process was formerly bruting, i.e., roughly shaping two stones by rubbing them against one another. In modern practice the stones are sawed with a revolving wheel coated on its rim with diamond powder, then shaped by inserting a holder, or dop, containing one diamond into a turning lathe that revolves it against a stationary diamond. The cutting of the facets and the polishing are done by a revolving iron wheel charged with diamond dust. After the facets are cut, the diamonds are cleaned and are ready for sale.
Sections in this article:
- Counterfeit Gemstones
- Precious and Semiprecious Gemstones
- Types of Gemstones
- Other Gemstones
- Diamond Cutting
- Gem Cutting
- Properties of Gems
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