OPAL GUY
An opal is a precipitated non-crystalline variety of silica, precious varieties of which characteristically display a marked variety of changing colours that are used as gemstones, especially when cut and polished.
Opal is found in many varieties, but precious opal is a remarkably small percentage of the total opal mined. Fine gem quality opal is more rare than rubies and emeralds.
The internal structure of precious opal makes it diffract light; depending on the conditions in which it formed, it can take on many colors. Precious opal ranges from clear through white, gray, red, orange, yellow, green, blue, magenta, rose, pink, slate, olive, brown, and black. Of these hues, the reds against black are the most rare, whereas white and greens are the most common. It varies in optical density from opaque to semitransparent.
