Gemstone - A precious or semiprecious stone that may be used as a jewel when cut and polished.
Cabochon: a highly polished gem that is cut convexly but without facets
Grading of Gem Stones
Gemstone and stone beads grading is less formal than gemstone grading as a whole. Still there are some generally accepted rules that determine which grade is assigned to a stand. Grade is assigned based on a letter with A being best and "D" being worst. Note that "D" might be just what you want for a specific project, so don't dismiss them as worthless. Sometimes you might see gem grades of A A A and A A. Those are real gem grades with A A A being near perfect. It's rare for such good quality stones to be cut into beads. They are worth more as faceted gems. The overall quality of the stones in the strand is usually derived from a combination of the classic gemstone qualities of color, cut and clarity. I will include more about grading in the next article but as far as I think you may have some idea about gemstones.
There are various kinds of gemstones like ruby, emerald, sapphire, amethyst, citrine, aquamarine and many more. These gemstones are found in different parts of the world and are imported by the suppliers and exporters direct from the mines as rough stones. These rough stones work as raw material for further processing.
Shape and size:
These rough edged stones are further decided to convert into shapes like oval, round, square, faceted, chips, smooth etc. and size as per the requirement.
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