How gemstones are shaped, faceted and polished

August 10, 2016 / Nicholas Pike

Have you ever wondered how gemstones are cut into the beautiful shapes you buy them in? At a reader’s request, we’re sharing the process with you this month:

People who cut gemstones are called Lapidary or Lapidarists. They shape, facet and polish gemstones.

image from www.langfordgems.com.au

To begin with, a lapidary chooses rough gem material which appears to have rich colour and has a minimum or no natural flaws,

image from www.djraregems.com

and then studies the uncut stone and chooses how to cut the stone so the gem ends up a maximum size and good colour. If the stone is cut well, it has the best colour, nice shape and no visible flaws to the naked eye. If the stone is cut badly, the stone may have poor colour, a not so pleasant shape or obvious flaws.

image from gemstone design: jonahstone.wordpress.com

Firstly, the rough shape is achieved by cutting the gem into a rough shape using a diamond saw (below),

and then grinding down further by using carbide grinding wheels. This reduces the rough material to an approximate representation of the finished stone.

image from afghanartsadventure.wordpress.com

image from nevada-outback-gems.com

After the stone is cut roughly to shape and size, the gem is cemented to a ‘dop’ stick, which allows the gem to be held against a small diamond grinding wheel which forms each facet.

image from www.pricescope.com

Finally, the gem is polished on a horizontal wheel, which is a much finer grit and allows each facet to polish and removes all traces of the scratches from the sawing and grinding process.

image from www.bespokegems.com

The image below shows a piece of rough amethyst in its crystal form, and the beautiful faceted, polished and shaped finished amethyst that was sourced from it.