Laminating a Curved Gemstone

I decided to try laminate some curved surfaces and then cut them into faceted stone.

This Hidi was just to do the proof of concept, just to see what play of light happens inside the stone.
I have laminated dozens of stones using HXTAL resin and and I always get clear and clean results.
Not this time. For some unknown reason, the two perfectly clean surfaces of the stone produced a couple of bubbles.
Right in the pavilion. Which magnified them over and over, virtually ruining the stone.
It looks OK just normally, but with magnification, it sucks.
That's just part of trying new things I have found. Plenty mistakes along the way.

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I like the color of blue and purple together.
So I had some really nice aqua from Zimbabwe and a piece of Brazilian amethyst.
Carving two comma shapes before.
Carving a curved surface so that it matches is not as difficult as it looks.

I do the basics first . Mostly with barrel shaped diamond burrs and water.
So the two inner curves of the comma would each be carved with a 4 mm barrel diamond burr. So then that curve on both stones is equal.
Then from that known curve, I work outwards on both stones.
I keep the two the same thickness, which provides me with another known for both stones.

Normally, if I have to set an expensive emerald or some other delicate stone, I use a spray powder called seat check disclosure powder.
It's a green powder that sprays out and coats the seat the metal and the bottom of the gemstone being set.

So the metal seat is marked and then you know where to remove metal
With patience and a billion sprays, you can get an unusually shaped stone to sit absolutely where you wanted it.
It also works well for gem carving because as you can see on the left side of the piece, the powder discolours where it touches, so that where you grind material off.
Later update:
If one uses a Sharpie and colors one or both sides, one can see where the stones touched and grind accordingly.
Seems much easier.

I use HXTAL resin to laminate the two sides together.

This is from some destructive tests I did to see if I could get the two pieces apart after being glue together.
As the picture shows, the material (CZ) broke before releasing.

I put masking tape on the clamp because if the resin comes into direct contact with the stone and the clamp, it breaks the stone before it releases.

I also weaken the clamp by annealing the back part so that it holds the two pieces more gently.

Once the resin is hard the stone is ready for pre forming.

The resin ground off.
Now I dop the stone and cut it on my Imahashi gem cutting machine.
I was going to cut this stone into an oval, because an oval reflects light in a bow tie shape along a center spine.
I thought that the 'bow tie' would change colour as it ran down the center.
But the amethyst developed a surface crack, so I had to make it's shape round.
With round, there comes a more even reflection of light which is not really what I wanted.
No matter, you go with the flow.

This picture was taken under an incandescent light.
I was cutting on copper with 7000 grit.

I clearly shows the different cutting surfaces between quartz and beryl.

The polishing rate is nearly the same, with the quartz being a bit slower.

I use a Batt lap with 50,000 diamond grit for polishing.

For some unknown reason a whole bunch of bubbles appeared.
I have no idea why, because the surfaces were meticulously cleaned before being joined.
Unfortunately it is impossible to see before the gemstone is finished being cut.

The stone came out at 10 mm in diameter and 3.6 carats in weight.
The reflection of the bubbles in the pavilion really ruins this stone and it's weird, because I have done over 35 other stones and only once did there appear a bubble.
That was because an ant was in the resin and I expect the bubble was gasses emitted from the expired ant.