I would like to ask your opinions about this boulder opal.

[phumv]

Hello
Today I got one boulder opal. I would like to ask your opinions about this opal.
Is it natural or man made?
The picture above is the one that I got today.

 

[stracci2000]

That is opal in man- made matrix.
In other words, the grayish looking stuff has been formed around the irregular shaped opal to create a cabochon shape. Not high quality, but pretty.

 

[phumv]

That is opal in man- made matrix.
In other words, the grayish looking stuff has been formed around the irregular shaped opal to create a cabochon shape. Not high quality, but pretty.

Thank you very much.

 

[Bron357]

Hi from an Aussie.
Boulder opal is opal found in ironstone. It’s found in Queensland, Australia. Here are two “raw” pieces that I have. You can see the dark brown red rock, that the opal is “on and through” which is ironstone.