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Andamooka Treated Matrix Opal

"Rainbow Matrix"

A great specimen

Andamooka is the only opal field in the world that produces Rainbow Matrix. For many years the miners have referred to it as Concrete.

However as marketers of opal we say we've got Concrete for sale. People think that we are in the construction business.

It has been unanimously agreed by the many people who are in the marketing of this product to officially call it Rainbow Matrix.

This is a beautiful stone that when heated and treated shows all of the colours of the rainbow. Not in every stone but some of the gem stones do actually show every colour in the rainbow. We have pieces from as little as $45 up to $975.

On the sales page we have some fine examples of Andamooka Rainbow Matrix. The stones have been sealed which gives them a very fine finish. They make wonderful specimens and the smaller stones, people are now making doublets from using many of them as pendants and rings. They look particularly beautiful in silver.

If you would like to share some of our Rainbow Matrix with us we would love to hear from you.

Kindest regards
More sales below

What in the world is "Rainbow Matrix" ?

So what's Rainbow Matrix ?

Andamooka Rainbow Matrix is a class of
Andamooka Treated Matrix Opal.
It is sometimes called 'concrete'.

It is formed in a much more porous limestone.

Because the matrix is so porous, it cannot be polished, and must be painted with a clear epoxy after cutting and shaping, or it will look as dull as the concrete on any city sidewalk...

The picture above is of a slab that has been wetted on the left side, and left dry on the right. It has not yet been 'cooked'. You can see that there is a marked difference between the brilliance of the fire on the left side and the barely visible fire on the right.

After 'cooking', this piece looks more like this :

So why does anyone care about Rainbow Matrix ?

Because it's Beautiful and Surprising !

If you do not paint it with clear epoxy after cooking, when dry, it will look very drab, with only a very faint suggestion of color.

But when it gets wet, it springs to life ! The best of this stuff will just knock your socks off !

Of course, you can coat it with a jewelers epoxy, and assuming that you do a good job or polish it well afterwards, it will always be just as dark and rich as the traditional Andamooka Treated Matrix Opal.

Want some of this for your collection ?

Here is a great piece of concrete that has been treated
and polished as much as possible.
It weighs 28 ounces and is a great specimen.

But it is already sold !

A great specimen

The slab below is a beautiful specimen.
It is 140mm x 35mm x 2 to 6mm thick, and weighs 2 ounces.

It has been cooked, but not coated with epoxy.
It is sitting in water...when dry, it is a dusky grey.
You can coat it, leave it as is, or re-cut it.


A very nice slab
more pictures
[1] [2] [3] [4] [5]

The following slabs are full of fire, and actually polish up pretty nicely.
(Not as well as good matrix, but normal Rainbow Matrix just won't polish...)
They have been lightly 'cooked' to aid finding.

The piece labeled (A) is 75mm x 25mm but varies from 5 to 2mm thick. It weighs 70 cts.

The largest piece (B) is 105mm x 24mm x 6mm and weighs 1.1 oz
It is nicely regular, not wedgie..

The piece labeled (C) is also nicely shaped, 65mm x 18mm x 5mm and weighs about 77 cts.

Piece (D) is really very pretty, but is a wedgie and would best be used as inlay etc. (35mm x 25mm x 4 to 2mm) it weighs 25 cts.

more pictures
[1] [2] [3] [4] [5] [6]
A very nice set
(A = 5587a) - $ 35.00
(B = 5587b) - $ 75.00
(C = 5587c) - $ 45.00
(D = 5587d) - $ 15.00

or $ 150.00 for the lot

Here are a couple of slices that came from the same origin, but exhibit the character of 'matrix' to be vary widely in pattern within the same stone.
Lightly cooked.

They are about 74mm x 24mm, and vary from 7 to 2mm thick.
Total 147 cts.

You can have both of them for $ 30.00
A very nice set
more pictures
[1] [2]

On to the rainbow matrix sale page
Back to the treated matrix page

Remember to just go to the Order/request page and let us know what you want.

You should also subscribe to the frequent EMAIL OFFERINGS, where we post our most recent offerings in email direct to you !

We look forward to dealing with you.

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Murray Willis