Fire Opal

I have heard different explanations of this stone. It is beautiful, it is certainly not the "sea of glass" or Opalite Opal, and what I found seems to be rather white fire opal from Mexico, although I have not seen an actual fire in the opal moonlight, only a warm glow. Is this a natural stone, and what are its real geological qualities?

I think Moonlight Opal is a common white opal mixed with mica, it adds a quality relflective to Opal, a soft moonlight.

I think it's also a natural occurring stone and geological qualities, I'm not sure.