"Light of the Desert", the world's largest faceted Cerussite gem carats), Royal Ontario Museum. Cerussite is one of the only gems with adamantine (diamond-like) luster. Very fragile. ITS THE ARKENSTONE!
Solid Boulder Opal - Rare pattern probably formed millions years ago then earthquake or ground movement cracked the opal. Also we assume potch filled in the cracks and set over millions of years again. THIS IS NATURAL OPAL, NOT MAN MADE!