Process of Manufacturing Gemstones and Cabochons
In the previous article I shared physical properties and some magical characteristics of Gemstone Beads. In the article, at first I would like to give a small introduction of gemstone who are new in this industry and some who want to gain knowledge about beads and cabochons. Let's have a look the meaning of:
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.
Cutting and polishing:
The skilled craftsmen in the manufacturing unit cut and polish the stone using modern machines.
Most however, are cut and polished for usage as jewelry. The two main classifications are stones cut as smooth, dome shaped stones called cabochons, and stones which are cut with a faceting machine by polishing small flat windows called facets at regular intervals at exact angles.
Stones which are opaque such as opal, turquoise, variscite, etc. are commonly cut as cabochons. These gems are designed to show the stone's color or surface properties as in opal and star sapphires. Grinding wheels and polishing agents are used to grind, shape and polish the smooth dome shape of the stones.
Gems which are transparent are normally faceted, a method which shows the optical properties of the stone's interior to its best advantage by maximizing reflected light which is perceived by the viewer as sparkle. There are many commonly used shapes for faceted stones. The facets must be cut at the proper angles, which varies depending on the optical properties of the gem. If the angles are too steep or too shallow, the light will pass through and not be reflected back toward the viewer. The faceting machine is used to hold the stone onto a flat lap for cutting and polishing the flat facets. Rarely, some cutters use special curved laps to cut and polish curved facets.
Finally these gems are used for making beautiful Jewelry. There are many kinds of jewelry tools that help to connect the beads and metals for making necklaces, rings pendants, earrings etc. Silver, Gold and Platinum are mostly used for making jewelry with semi precious and precious beads.