Process of Gemstone finishing:-
The gemstones are known to humans since the beginning of civilisation and since then these are finished in various shapes and sizes as per needs and choice of the humans.
- The gemstones have always fascinated human beings with beautiful colors and shiny surfaces.
- The gemstones cutting and finishing have undergone a dramatic change since known to us from hand crafting to use of advanced computer technology for better and advanced finished stones.
- The history of finishing gemstones begins with working on metal plates giving shapes to gemstones with holding rough piece in fingers.
- Initially in India people used to do this with hands using tools called as “Randa”, it is a tool with plated attached to rod on side like a dumbbell and on the other side of rod there was a thick white rope like thread holding a big bamboo stick using which metal wheel can be rotated.
- On Rotating metal plate a green colored chromium oxide powder was used to finish the gemstone giving specific shape.
- The above traditional system is still in use for soft and expensive diamonds and stones like “Emerald”, where high yield is very important.
- With the invent of motors the hand randa is replaced with motor, now it’s just a high speed rotating metal plate fed with fine diamond powder mixed with coconut oil attached to motor but still in India pre-shape of rough stone is done with rough piece holding with fingers for better yield and desired shape.
- The worker saves his finger tips covering them with balloons.
- The shape and causes of color in gemstone is decided giving directions to rough gem crystal with fingers on fast running metal plate.
Advancement in gem cutting:-
- Nowadays most of gem cutting units in Jaipur use technology developed by Israel.
- Pre-shaping rough gem crystal with hands on motor run metal plates.
Then size of preformed gemstone was finalised on machine called as “MM machine” in general market.
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- Each and every crystal was checked with vernier calipers or MM watch (Technically called as Milimeters Gauze) Then gemstones are transferred to another process called as Dopping.
- Dopping involves pasting calibrated gemstones on Dopstick.
- Dopstick is a handheld device with different angles marked on it and these angles help in making facets on calibrated gemstones at a particular angle for maximum brilliance.
- Some years ago instead of metal dopsticks wooden thick pencils are used. Dopping process involves using thick brown clay heated with flame arrangement on table of dopper (Worker who carries the dopping process).
- The melted clay sticking at top end of dopstick will hold calibrated gemstone, then worker with hands by pressing melted clay hardens.
- The important point to remember while dopping is matching cult of calibrated gemstones to top part of dopstick.
- The gemstones attached hardly to dopstick are now handed over worker seating on israeli factor which is a tabular machine with two high speed running plates on table top with plates attached parallel to the table top.
- One plated has water flow arrangement used for making facets on calibrated gemstone while other plate runs dry with diamond powder feeds for polishing.
- On single table a worker can facet and polishes a gemstone for final finishing.