faceted rainbow moonstonefaceted rainbow moonstone

Advice for Preforming Gemstone Rough for Maximum Yield

To pick the right cut for a gem, you need to figure its maximum potential shape. Preforming gemstone rough is essential for making the design a reality.

Question:I just read your article on the minimum cutting technique for gemstones and thought it was excellent. I do have some questions. What would you recommend for shaping and preforming gemstone rough for maximum yield? Did you use a cabbing unit with a 100 grit diamond wheel? I've been using my Ultra Tec faceting machine with a trim saw. Now I'm wondering if it would be faster with a grinder and 100 grit wheel. Any suggestions?
preforming gemstone rough - Peridot
Peridot rough, Pakistan. Photo by Jarno. Licensed under CC By 2.0.

Answer:Choosing the right cut for a gem is challenging. You must weigh many factors. One of the first things you need to determine is the maximum potential shape of a piece. Using the right equipment when preforming gemstone rough is essential.

The Best Equipment for Preforming Gemstone Rough

Thank you for the compliment. It's nice to know people appreciate my efforts. I use the 80 and 260 grit wheels on my Diamond Pacific Genie for preforming gemstone rough, depending on its size and hardness. An 80 grit wheel isn't nearly as tough on rough as an 80 grit lap.  If you're working on your Ultra Tec faceting machine, try something around 260 for shaping.

It is somewhat easier to shape your rough with a cabbing machine like the Genie, but it can be expensive. Unless you intend to do quite a bit of cabbing as well, purchasing one just for preforming rough wouldn't be worth the expense.


Donald Clark, CSM IMG

faceted rainbow moonstone
Faceted rainbow moonstone. Photo by Amelia Isa. Licensed under CC By-ND 2.0.

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