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How to cut opal – see a gem emerge from a rough opal

How to cut an opal - 25.50ct black opal

How to cut opal: cutting challenge #3. A customer recently bought a rough piece of opal and was unsure how it should be cut.

He decided to send it back…

Normally we would re-list the stone.Justin decides to take on the opal cutting challenge that he has been presented with.

The video is a long one at 21 minutes but you will see the whole process as well as tips and advice on the following:

  • Assessing rough opal for colour.
  • How to decide which way an opal should be cut.
  • How the dome is formed on an opal.
  • What grades of diamond wheels are used when.
  • How to achieve that final perfect polish.

For those not keen on cutting opal themselves you will still find the video fascinating as a gemstone is revealed layer by layer – and you will be well on your way to understanding how to cut opal at a pretty expert level!


  • Lisa

    Stunning stone Justin. Your expertise makes opal cutting look easy. Hahaa.
    Is this stone sold?

  • MHT

    Hi Justin,
    Have a nice day. Enjoyed this lovely and live nobby opal cutting video. Excellent result after cutting. I like nobby opals because you do not loose the value and it gives more room into cutting it and bringing out good finished opals on condition that you are a seasoned lapidarist. Practise makes perfect.

    Best wishes,

  • JP

    You did a fantastic job Justin. Love cutting stones and really miss not being able to do so anymore. You make great and informative videos, keep up the good work.

    • Thank you JP and I am sorry you are not able to cut opals. I hope I can keep the dream alive for you in my videos

  • Chris Crevier

    I enjoyed your video very much, because it was not only informative and interesting, but because I always wondered how my few pieces of opal jewelry were made. It helped me to understand how much time goes into the jewelry I wear and the price I pay. So thank you for taking the time to make the video.

  • stefano

    I have several black opal stones and I have one side revealing the opal colors but I wanted to remove the outer shell completely . Is there a way of doing this at home.

    • Hi Stefano Yes you can do work on opal at home but you need some sandpaper to wear down the opal. It is not a way I would usually tell someone to do it but if you have no other lapidary tools this would be the only way. I hope this helps

  • Paul Schipper

    Thanks very much for your videos, Justin.I am a total newcomer to this but find it fascinating. Is it really possible to increase the value of a rough piece of stone like this?! Quite amazing. Would you have to spend a lot of time learning how to do this? Cheers. Paul