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Kinds of faceting, cabochons, glyptic
Kinds of faceting, cabochons, glyptic
There are following kinds of a facet of semi-precious stones:
1) polishing, or stepping - emerald; 2) wedges; 3) rose; 4) diamond; 5) mixed or combined; 6) fantasy; 7) cabochon.
The main goal of a facet is preservation of weight of a stone.
The facet frequently corrects defects of growth and various deformations of a crystal, opens the optical properties inherent in the given mineral.
For some semi-precious stones, especially translucent and opaque, optical effects are peculiar:
opalescence, irisation, asterism.
To them give usually hemispherical form - cabochon which strengthens the specified optical effects.
Cabochon may have the concave, convex or equal basis, various elongation and height.
From richly painted stones it is accepted to do high cabochon, clarifying a stone; the mixed polishing is sometimes applied: half of hemisphere of cabochon is polished, on another make edges.
It is necessary to tell about a groove on a gemstone.
Art of a groove on semi-precious stones - glyptic - is known from an extreme antiquity; it is more senior than a sculpture, painting, goes back to sources of a human civilization and its stone annals.
Wares with glyptic have reached us are the unique reflection of their high and original culture.
The periods of bloom of glyptic alternated with the periods of oblivion of this kind of art.
Kinds of gemstones on which cut out images were replaced, the tool was improved, but there was constant a manual method of work.
Now many people who like glyptic, take a great interest in manufacturing of carved stones with recessed (intalio) or convex (cameo) images.
For this purpose it is applied reinforced by firm alloys or the diamond tool.
However now art of glyptic yet has not received a wide popularity.
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