The definition of the opal is
"Non crystallised minerals made by silicon dioxide combined with water".
Do not panic. This is not what we are going to tell you. But this is the definition. And it means.....,
Do you know things in a small bag which you can find in a package of rice crackers or sometimes in a package of a computer?
Maybe you don't know.
Ok, how about this.
For protecting clothes from humidity, some people put a product called "silica gel" in their closet.
Yes this is it!
We believe you have some kind of idea about these tiny blue particles, this is OPAL. But don't think like "opal is just a cheapie thing".
We say that, because it will give you a little idea about opal. In a manner of speaking, we can say the diamond is the same as "coal" or "pencil".
Opal itself is made from the same mineral "silica gel", but the comparison to these opals, is one takes more than 6 million years to form and silica gel and the other takes few hours to make in factory by a human.
We believe you can understand the value difference between these. Also "silica gel" doesn't have beautiful or brilliant colours.
What do you think? Do you think you have different recognition in opals now? So we are going to explain the reason why the opal is so unique, and what type of character it has.
The reason why many people have a fascination for opal, is its colour. Especially the Black and Boulder Opal from Australia, we can say that each stone has a different and unique colour (There is no same colour stone). Also, even one individual stone can produce various colours depending on the lighting or which way you look at it.
Why each stone have such a unique image? We are going to talk about that in ADVANCED, but let us tell you this unique colour which any opal has.
It's called a "Play of Colour".
What a beautiful sentence!
We don't know who said this at the beginning, but this is the right word for the colour of the opals, don't you think?
When you see a good quality of Black Opal, you are the prisoner of the colour.
Have a look at these pictures.
These are the photos of same stone but under different lightings.
The left photo is the light comes directly above the stone, the right photo is the light coming from the side of the stone. We have not added extra colour or paint.
This is the "Play of Colour".
You can find the photo on the left hand side has shown different colour changing from orange to green depending on the lights.
If you see 100 stones of opals, you can find 100 different colours from them. This is the main reason why opal is so unique compared to other gems.
The pattern of colour has its own name, and it is very important aspect for valuing. We are going to talk about colour patterns in the chapter ADVANCED. So we will go forward to the contents about "types of opal" and " produced area".