Natural Blue Obsidian (raw) Obsidian is a very special stone. It is not a true mineral. It is actually a volcanic glass that forms when molten lava cools too rapidly to crystallize. It consists mostly of Silicon Dioxide.
"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!