Author: Peter at Petros Rocks

Marquise type solid crystal opal

Posted on by Peter at Petros Rocks

Red rolling flash

Marquise crystal opal loose

Marquise type solid opal

As soon as the skin had been cut back, even with a low grit, the colours were bouncing back off the wheel. It’s well covered, with pieces of  floating and sunken multi colour along with a rolling flash of golden yellow under artificial natural light.

Cutting back potch and sand, the shape evolved to a Marquise type shape. The stone slopes thinner to one side at one ‘end’. However , this is such a lovely stone with clear bright colours,  that set correctly, would make a stunning piece.  I’d play with a darkened setting, but even resting ‘as is’ on a finger, it looks lovely. There is a small inclusion to one side but this is not on the face. Again, correct setting would render this invisible.

 I did enjoy working on this piece of crystal opal. It’s around 14mm x 6.4mm, 2 – 1.6 mm deep and weighs 1.1 carats.

My photography skills don’t do justice to it!

I’ve taken the photographs in a near daylight with an artificial source. Please feel free to comment on the post and photographs.

Multi coloured fossil opal with rolling flash

Posted on by Peter at Petros Rocks

Multi coloured fossil opal with rolling flash,

A multi coloured solid fossil opal with an additional rolling flash. This loose stone ranges from about 2mm thick to about 1.5mm.  Size wise it’s around 12 -10mm and weighs in at 1.65 carats.

It looks like this was originally some type of shellfish where in the fossilization stage, the shell has been replaced by opal. It comes from Coober Pedy and the area known as  ‘Diggers Gully’.

Due to the initial shape of the shell, this took some time to cut but as you can see,  it polished up very well.

I haven’t really been able to do this stone justice with the photography. clarity and colour of the flashes aren’t as sharp as in ‘real life’  but I’m sure you get the idea! The back of the stone, although not polished, gives a lovely golden yellow broad flash.

I’ve taken the photographs in a near daylight with an artificial source. Please feel free to comment on the post and photographs.

 

Mainly red rolling flash…

Posted on by Peter at Petros Rocks

Red rolling flash

Mainly red rolling flash solid!

This solid opal is from rough from Coober Pedy, an area known as ‘Diggers Gully’.  A very attractive stone.  This was showing it’s colour flash through the ‘skin’ in it’s rough opal state.

I took my time cutting this one.  There was some sand in the side which I’ve removed.  It’s always a fight when you have patches of bedrock or material in the body.  Sometimes it can be left and adds a uniqueness to the opal.  In this case, it needed to come out! I had to lose some weight but it was worth it. 

Besides the broad red rolling flash , there is also orange, yellow blue and green in this opal.

Cutting the back gave yet more flashes of red fire !

I’ve taken the photographs in a near daylight with an artificial source. Please feel free to comment on the post and photographs.

Red and Green oval opal

Posted on by Peter at Petros Rocks

This red and green oval opal came as a bit of a surprise.

It was a piece of rough that was curved with a skin on both sides.  The edge had a bit of colour play but I knew due to the curve, I wouldn’t really be able to make a solid stone from it.  Out came my black agate.  After flattening both the rough and the backing, I married them and left to set!

This one took quite a bit of care.  It was fairly thin and the surface as well as being convex undulated quite a bit. Grinding little and inspecting often is the key.  To start with I believed I’d have a green pinfire flash but as tends to be the case with opals, this changed as the grinding and polishing continued.

The resulting stone has a greeny pinfire.  Then, when you turn it, you get a lovely redish glow flowing in form the sides. It’s more like a traditional doublet as the piece of opal is thinner than I tend to use.

 

 

Rainbow crystal opal

Posted on by Peter at Petros Rocks

crystal opal

A rainbow crystal opal!

This was a piece of rough crystal opal that had come in a batch from Australia.  It had a slight dull flicker of rainbow colours and was on a sandstone backing. The original stone was cracked into three and I tried hard to work with the pieces but they were really quite small and fiddly.  I thought I’d have a play and mount one   onto black agate,  primarily so I could cut and polish the opal more easily.

I used a two part crystal clear epoxy and made some lamp black to darken it down. After waiting, I  dopped the stone and then trimmed the back down .  Everything felt much easier to control.

It was a real joy to work on! Every part of my cutting and polishing revealed more colour, vibrancy and brilliance. There is a small inclusion of sand on one edge but to remove that would have meant effectively destroying the stone… you can hardly see it without a loupe. When I reached the 3000 grit, the rainbow colours were really showing through.

The final polish gave me a big smile. It may only be a small stone and effectively it’s a rather thick doublet but I love it.

I’ve taken the photographs in a near daylight with an artificial source. Please feel free to comment on the post and photographs .