166ct Rough Opal

I have been putting off cutting this piece of 166ct rough opal.
The approach to a piece this large takes a little more patience and brainpower, especially when it has a myriad of problems to navigate.
However, this piece was my son Saxon’s choice for our next cutting video, so here we go!

Turning A Challenge Into A Gem

First things first, a quick check with my trusty gemfish flashlight (find it here) revealed some good news: the color bar was clean, and there was a flat potch line at the bottom — boom! Fire up the cutting machine and let’s start cleaning it up.

As I worked, I noticed the black potch started showing up, but the sand was creeping in deep, making the dome smaller than I’d hoped.
It was clear there were two main color bars with a thick potch line in between. To salvage the best of this opal, I decided to slice through the sand and potch, hoping to reveal something spectacular.

The first slice showed some beautiful colors, hinting at the potential of this stone. However, I faced a dilemma: the color bar was thinning out on one side, making it risky to slice off the top for an extra gem. Instead, I focused on removing the sand and potch to expose the vibrant color bar underneath. As I continued, the color bar started to emerge beautifully, despite some gray webbing. I was thrilled to see the potential of this opal coming to life.

A 166ct Rough Opal to a…

In the end, it was a big win. Cutting this opal was a rollercoaster of decisions and surprises, but that’s the joy of working with these incredible gem opals. What do you think? Did I make the right choices, or was there another path I should have taken?

Spolier Alert

38.63 ct dark opal 33×21.7×8.1mm


In stock

SKU: YTV24001

2.61 ct dark opal 12.3×7.3×4.5mm


In stock

SKU: YTV24002

5 thoughts on “166ct Rough Opal”

  1. “Veni Vidi Vici”!

    As I’ve said, in the video comments.
    You’ve Risked and succeeded.
    I watched ever step very closely.
    You assessed, then took the first cut to inform yourself
    of what the stone showed. You couldn’t have sliced the top for 2 stones.
    The flagstone, blue and green layer wasn’t remarkable.
    It was cloudy with gray potch.
    The Pinfire below was the way to go and revealed many more colours.
    It’s a Huge Cracka! A Beauty!

  2. As I have said in the comments in almost every video you have made, you are a master at this. I have learned so much from you it’s getting to the point where i think i know what your are going to do next as you are shaping the stone,… we’ll amost. As far as this huge opal is concerned you made the right choice in not cutting the top off. It turn out absolutely gorgeous!!!!! both of them. you may not believe this but after a long hard and hot day watching your videos puts a smile on my face and I am in a better mood. thank you

    • Thank you for your constant support Thomas, so glad our videos bring a smile to your face, mission accomplished!


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