Opal

There are as many worlds as there are kinds of days, and as an opal changes its colors and its fire to match the nature of a day, so do I.'

John Steinbeck

October Birthstone

Opal and Tourmaline are the birthstones for those born in the month of October.

What is Opal?

Opal is formed from a solution of silicon dioxide and water. As water runs down through the earth, it picks up silica from sandstone, and carries this silica-rich solution into cracks and voids , caused by natural faults or decomposing fossils. As the water evaporates, it leaves behind a silica deposit.

 

What is Precious Opal?

"Precious opal" is the name used for any opal that exhibits "play-of-colour". Play-of-colour is the familiar flash of bright colourful light that a person sees when viewing opal. Black opal, white opal, crystal opal, boulder opal, and matrix opal are all varieties of "precious opal".

What is Play-of-Colour?

Play-of-colour is an optical phenomenon that occurs when light enters an opal, interacts with its internal structure, and leaves the opal in a flash of spectral colours. A single piece of opal can have an almost unlimited number of appearances. Its appearance will constantly change::

  1. as it is moved under a light source;

  2. as the light source is moved, or;

  3. as a person changes their angle of view.

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