Opals, a Breif Introduction. Part I

Opals are amazing and truly unique! Every Opal is different than every other Opal even though they are molecularly similar. So what makes that brilliant flash? In a word, Silica. When light penetrates the rock and hits silica orbs infused with water, they act like a prism and bend and separate the light into all the colors of the rainbow. That is the secret to the amazing play of colors we see in these rocks!

Even though Opals posses the same light manipulating properties, no two opals look alike. However it is very interesting to compare Opals from different mines. Maybe I have spent way too much time looking at Opals but I can see some distinct characteristics that are unique to particular mines. Let me show you what I mean. 

https://www.pinterest.com/pin/118993615130836647/

 

To the left, you see Mexican Fire opals. They are a yellow to amber color with flashes of color all through out. Mexico is known or these types! I'm sure there are other places that have opals that resemble these but I haven't seen them yet.

https://www.opalauctions.com/learn/opal-information/australian-opal-fields

 
To the right you see an Australian Opal. It is blue and green and orange. Australia has a massive diversity when it comes to Opals. They have black, white, boulder and crystal opals. And each of those genera has a massive amount of diversity within it.

https://www.opalauctions.com/learn/how-to039s/how-to-identify-

 

This is an Ethiopian opal. The only way I can really explain the difference of this type of opal is the way it reflects color. It seems like it is on the surface of the Opal. And I usually get a lot of green and red when I order from there.




Because the radiance of the Opal depends on the amount of light that is able to penetrate it, domes are preferable and most common. Sometimes I see them faceted but I wouldn't say that adds anything to the stone at all, they simply aren't that kind of rock. Because Opals by nature are entirely unique, each and every one, that is why my preference for cut is free form. I feel it enables a rock to retain its individuality.
Something else to keep in mind is the level of diversity. These rocks are examples of what I commonly see from a particular mine. That does not mean that all rocks that come from these places look like this. Sometimes opals from Australia look like those from Ethiopia etc.

This is a topic I am passionate about so if you have any questions or comments feel free to message, comment, email whatever strikes your fancy!