Green Monster Opal - 4800 carats

The Green Monster opal is a huge chunk of brillant green Andamooka matrix opal, owned by Riley Gunn of nnOpals (53 Frogs on Opal Auctions).

The stone weighed approximately 4800 carats initially. In the video, I tumble and grind the huge rough opal, then treat it with concentrated sugar, then concentrated sulfuric acid, which was successful in that it turned the background black! (Andamooka matrix opal treatment success is judged by how well the sugar and acid penetrate into the stone.) Sulfuric acid reduces sugar molecules to pure carbon, which is black.

Matrix opal is normally light tan to white in color and the "fire" is difficult to see. With treatment (if successful), the background becomes black, and the enhanced contrast makes the color is easy to see.

The quality of matrix opal can only be judged AFTER it has been treated (if the opal has minimal visible play of color in the untreated state). Such untreated opal has no real value for jewelry because its color is imperceptible. Treatment is therefore necessary.

Safety is an important aspect of working with concentrated acid of any kind. Hazardous material gear is absolutely necessary. Clothing must cover all exposed parts of the body and a hazardous material respirator that is rated to handle acid is necessary. Eye protection is imperative and a respirator mask with face shield may be best.

In the video, I treat the stone to identify the color, then I sliced parts off to be made into cabochons. Gemstone cabochons, for jewelry. Smaller pieces were used to make two small arrowheads, which are beautiful. Cabochons, arrowheads and opal flakes are being given away.Concentrated acid must be disposed of in the manner required by law in your location. You may contact your local authorities to get the requirements and directions in this regard.

We thank nicethingspro for the use of their excellent parody video "That's Not A Comb"

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