Anyone treated fairy opal before?

[Keen Ken]

If the opal replaced the limestone wouldn't the whole stone be opalised?,and not opal impregnated as it appears to be under magnification. You can see the sand grains.
The use of the work "concrete" on the opal fields has been used for decades.
My guess would be the use of that word has given rise to the thought of the matrix consisting of some sort of limestone, which we know is not the case, else the sulphuric acid would dissolve the "limestone" during the treatment of the matrix.
I did try the acid-sugar treatment years ago on some Queensland sandstone matrix (like what was pictured). I found the sandstone had a fair percentage of gypsum which dissolved and the sandstone fell apart.
I do know the commonly used technique for blackening and stabilising sandstone matrix but this process is now under patent (not by me). Not willing to risk my neck here.

 

[shivan]

G'day Ken, when i first read about talk of the Andamooka matrix being limestone and the opal being impregnated i assumed it was similar to the sandstone. As i have only looked at photos online it is hard to make out any fine details.

I was wondering if perhaps the opal only partially replaced bits of the limestone, or if it was replacing the whole rock? Because if it was fully replacing it, i would think as you say it would just be opal and not a matrix opal? But if it only partially replaces the limestone one would have to think the rest of the limestone was at least altered if not replaced by something else because there seems to be no reaction during the acid stage of treatment?

I guess a bit more reading is in order.

I do know the commonly used technique for blackening and stabilising sandstone matrix but this process is now under patent (not by me). Not willing to risk my neck here.

I fully understand, again i am just happy for some conformation that there is a different treatment for the fairy opal. I did read about a company claiming to have their own patented technique for treating fairy opal, but was not sure if they were talking about acid or not.

As i said i have some opticon handy so will give that a try on a small piece after treating it with sugar, if it works great, if not nothing lost from having a go.

 

[Keen Ken]

Hi Doug,
I did experiment with sandstone matrix opal placing it in "Spirit Stain" (ebony in colour) with mixed results. It did substantially darken the sandstone but having bigger fish to fry at the time I left it at that. Our material was rather soft and needed stabilising with resin.
I used to pay a guy to carbonise and stabilise preshaped pieces at a cost of 50cents per gram for each process ($1 per gram for both processes).
Some came out really nice but most was just pin fire green, blue or pink predominantly. There was a small percentage that had lovely blocky patterns of intense green.

Not including my time sorting, sawing shaping and finishing it was costing about $10 per piece, so to make it worth while we needed to sell each piece for around $25 to $40 to be able to make any money. Not a big seller.

Most pieces were about 20mm x 15 mm x 5mm thick.

This was a by product when mining for pipe opal, when times are tough you will try anything to make an income.

 

[shivan]

Its a shame it did not sell better for you. I think some of it looks really nice, but i have heard a lot of people say they wont waste time with it. But after treatment and playing around it does seem to add up.

Was there much of it around?

Hi Doug,

Oh its Ian by the way..... Unless you were talking to someone else? :lol:

 

[Keen Ken]

Sorry Ian,
Just messaging someone buy the name before,
There was not a great deal where I was working.
The pipe opal occurs in gutters and the fairy opal with it on this particular field, if gutters were deep and the pipes were bright there would be some fairy opal along with them, didn't need to be much pipe opal, just good colour. The pipe opal of course is of much higher value that's what we we're chasing at the time, we kept everything as you can't tell when the next patch of pipe is going to come out.
When we came up with no reasonable pipe opal we had to treat the sandstone matrix to try and recover costs.
Yes it is beautiful but if you are trying to make a living it's very difficult to on fairy opal alone, let alone cover mining costs.
Unless you have substantial amounts of top hard material.
Areas around Opalton and Jundah have more substantial pipe opal deposits and i've been told in some places 1 foot thick and hard as concrete.
I was given some of that material and the colour was superb, it looked similar to top Amdamooka matrix in colour and pattern once carbonised.

 

[shivan]

Ahh well there goes my dream of a sandstone brick house made of fairy opal

Thanks again for your replies, sounds like opal mining can be a hard slog, but it still fascinates me.

 

[yash singh]

I want this rough 1000 kg any help me.

 

[fossickeract]

Hi Ian,
I picked up some " fairy stone" looking like yours at Opalton couple years back, and experimented unfortunately I can only tell you what doesn't work. Soaked some slabes in olive oil then baked in oven. It was stable but a dirty brown background and not really attractive.Have been told diesel has been used before baking to give a better result. Second batch was soaked in honey solution(sugar) then treated in Sulfuric Acid. This came out very attractive but crumbled the acid had attacked the matrix.Its a sandstone matrix but seems to have calcite binding. Cabbing before honey treatment and quick coating with epoxy when dry after the acid worked but still not solid enough for jewellry use.
Cheers Ted

 

[Rema Exploration]

Hi there
All you need to do is use normal cooking oil
Start a charcoal fire in the ground just make sure no drie grass around because some of the stone may cause some firework.
Rap the stone in aluminum foils twice. Put them on top the charcoal when they nice and hot and cover them again with charcoal. Leave them in for 10 minutes. After that remove one out and check.
If the stone still wet in oil putting back for a nother 5minutes.
Make sure they get even heat ? all the way rounds.
Repeat the process for all the material.
After that leave them out to cool down.

Remember some time you might need to repeat carbonizing process couple time
Specially if you end up rubbing to mutch.

The trick is how to get a good polish
Remember sandstone is poress.
You must start with fine granual sandstone.
The material has to be stabilised and treated after carbonizing.
If you need some advice reply
I will try upload 1 piece of our product.
It's the best finish product on earth

 

[Rema Exploration]

There some more photos of finished product
We are the source we are the miners

 

[Matrix007]

Fairy opal is boulder opal matrix, rainbow matrix is a sandstone matrix from Andamooka it was called cement or concrete now rainbow matrix, it some times has small stones or just sand cemented together with Opal, it can be treated with sugar and heat to turn the sugar to carbon, Andamooka matrix is several types of sandstones that the Opal has saturated, some times the matrix can have too much Opal and can not be treated but good matrix can be treated with sugar and acid to turn the sugar to carbon, many people have special or secret ways to do this but you can find treatments on the net, painted ladys are formed when the Opal is liquefied and seeps into the cracks of rocks then solidifys and joins the rocks back together if they have colour they are called painted ladys if it is just potch inside they are called bitc..es there are many types of stones and rocks in the Opal levels quartzites agates and many more, if thease have been saturated with the liquid Opal for long enough even thease can be Opalised, I hope this is of some use to any body with the same interest.

 

[Matrix007]

One of the better ways to fill small holes in Andamooka rainbow matrix after cutting and cooking is using star bond thin then repolish start at 600 - 1200 then final polish, I have polished rainbow matrix to #3000-14000 and still get good Finnish on the stone without any other glues or stabilisation, don't use powder polish, if you are in Andamooka talk to the old fart at the Andamooka lapidary club.