77.8 grams Andamooka rainbow matrix untreated. [BZ500]

Item Information

Dimensions (mm) 71 x 44 x 20mm
Weight (carats) 389 carats

This is a natural untreated andamooka rough slab.  You can have the fun treating it. We have hand selected this out of a large pile at the miners camp where we selected 300 kilos of this rough . As it is from different opal fields around andamooka you will find some variation in absorbency when treated.
You can reshaped it or cut into smaller stones but you will have to retreat it. Check that there isnt another colour bar in the rough you cant expose that may be better than the top.
Mined in Andamooka South Australia
This is andamooka matrix called Rainbow opal matrix

250 grams glucose,white castor sugar,pot or pressure cooker,plastic tweezers.
-Preshape the material

- Thoroughly dry the material in oven sun or hairdryer. You can also soak in acetone for 10 minutes to dry the stones out.
- Put water in pot on low temperature and add glucose and castor sugar. DO NOT BOIL.
-Place warmed stones into warm solution and cover the stone with liquid.
-leave on low temperature for 24 hours but DO NOT BOIL.
-Remove with tweezers and let cool.Use a paper town to wipe away access.
The next steep is to carbonize the sugar in the stone. Place the stones on a metal or Pyrex dish and place in a kiln at 500 F degrees for one hour.This will burn or carbonize the sugar in the stone.
_When the stones have cooled clean on a grinding wheel.
Remember to take all precautions with gloves and mask and clothing with good ventilation.
This is a natural product so results may vary a bit due to how porous the sandstone is. Some material will have to be treated a few times to get good results. You can also experiment with various temperatures as i like to cook with lower temperatures.
Remember to have fun!
In the learning section of opal actions there is details on how to treat with acid and sugar but this sugar only gets good results on porous materiel
This material is very solid

 The surface is usually porous porous so its hard to get a good finish but this should give good results and you may be able to polish as is..
You can polish as a natural stone or coat it with resin to get a better finish.
We suggest a polymer resin as its stable.inert and nontoxic and dosent yellow..Check out our listings of fairy opal polished in sedaopals.Some of there were polished in china under vacume with a amazing finish.
We have also used mono-compontent thermo set resin,cynoacrylates and 2 parts resin but these can turn yellow over time. ive even heard of nail polished used and hardened under uv lights.

The weight and size is app
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$65 sarthen
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Pricing & Details

Bid Increment $1
Starting Bid $65
Auction ID 1114266
Watchers 1 watching
Viewed 164 times
Starts 18th Nov 2021 7:10pm PST
Ends 21st Nov 2021 6:50am PST

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Seda Rough Opals Details

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