Unique Lightning Ridge Black Opal

Photo by Wood's Stoneworks and Photo Factory on Flickr

Opal | ‪#‎Geology

Formula: SiO₂·nH₂O
Colour: Colorless, white, various
Hardness: 5½ - 6½

Lightning Ridge Black Opal it is like lightning bolts that flash and change as it moves. Australia. 

  

Types of opal with photos