Unusual specimen of Mexican Opal with Rutile inclusions It is a mystery on how this Opal was formed this way. Opal is silica and Mexican Opal is volcanic so to have rutilated needles form inside the silica or Opal it needed to have cavities.
Gem quality opal from Australia. SEM Image of the opal. Compare near-gem quality opal and gem-quality fire opal x magnification) from (dry) Lake Tecopa, Inyo County, California, USA; SEM images courtesy of Ma Chi
This is a beautiful boulder opal I mined in 80 carats, I call it "Bushfire" as it has all the greens mixed in with fiery oranges and yellows. Bill Kasso PS it came from Shaft Gully mine in Eromanga, not far from Hammonds.