This is a natural koriot rough that we have sawn open to expose the colour. The precious opal is embedded in the host rock.This material may have natural holes in it and the sandy areas are hard to polish.You may polish it naturally or in asia the cutters rub fine boulder ironstone [you can collect this in the cutting machine tray by grinding some material away and allow to dry]. They then rub this powder in to the rough and heat it up.Then they apply super glue to it and polish.This gives a good glossy finish.
They are also ideal as specimens natural or polished
Weight 90.95 cts app
size 37 x 34 x 8 mm app