Slow Opal

[PinkDiamond]

That's a good one for sure. Do you have a rock saw or are you doing it by hand? If you find someone else to do the wire wrapping you can always show them a sample of one like John showed above and ask if they can do something similar.

[skywalker753]

So I haven't really said anything about the process I developed and use for the carbonization of the matrix/host rock. In general, its 1) dry the matrix opal out after its been cut and almost polished. 2) Hot soak it in sugar water for a number of hours. 3) Cook it so the sugar carbonizes and creates a dark/black background and the opal bits sparkle. 4) Final polish.
But, I bet as many people who do this themselves in the world, have their own way of doing it. Here's just a bit more on mine, not saying its any better than anyone else's way.
OK, so the two things I use are a 4 quart/liter air fryer-- yes, I said an air fryer, and then a cast iron kettle with lid. It works good. I heat the matrix to 185-190 F in the air fryer to dry it out pretty good. Then put a cup of sugar water in a metal container, put the matrix in that, and put that right back in the air fryer at 195F for a number of hours. It shows the temp and time you set, and you leave it for a while. My minimum time in the sugar has gone up, and is now about 6 hours minimum, and overnight sometimes. Then I take the matrix out, blot it with paper towels, and put it back in the air fryer by themselves for 30 minutes at 195F again.
Then out they come, I wrap them in layers of alfoil/aluminum wrap, and put them back in the air fryer, but now at 400F for 30 minutes.
While thats working I turn on the camp stove (gas) and get the cast iron kettle with an inch of sand on the bottom pre-heating on between low and medium on the heat dial. (Wish it was exact temp wise, its not) Whenever I think the cast iron kettle with lid is up to temp, I go get the alfoil wrapped matrix, and put it in the kettle, for about 2 or more hours. This is when it carbonizes the sugar in the matrix. About an hour after it starts stinking from burning the sugar, its as done as its gonna get.
Take it out, let it cool, polish like usual. If that sounds complicated, its not really, you're just getting the matrix ready to carbonize, and then carbonizing it...lol...
And, I don't use sugar. Well, it is sugar but its not. I make maple syrup here, so have plenty on hand, and I use that diluted a bit. Works fine. Smells pretty good too in the steps before the carbonization...lol...
Thats it for now.

[PinkDiamond]

You make maple syrup? I guess that means you have sugar maples? I have always wanted maple trees here since I love maple better than sugar, and I usually replace white sugar with granulated maple sugar in recipes. That's amazing that you use it for sugaring opals, and thanks for describing your entire process for anyone who wants to give it a try.

[skywalker753]

Ya, got some maple trees here. 300 plus but dunno exactly. Maybe total of 900-1100 total. Don't use them all for maple syrup so haven't counted accurately.
Anyways thats a different story...lol...
Right now I'm just hoping that no matrix opals blow up this batch. They're cooking now. When I do lose a matrix opal in the cooking phase, it used to be almost always my fault, meaning I did something wrong. Now the blow ups are far fewer (still happens tho) and the successes are far more. Mostly now its because I saw a crack but ignored it because it didn't fit what I wanted to cut. Bad idea... or tried to speed up the process by turning up the heat too high. .....Man's got to know his limitations......(old Clint Eastwood line in a movie)...lol...

[skywalker753]

If you click back to page three, scroll down to the bottom, you'll see where I just sliced a matrix opal in two: One good side (color!!!), and one with just about no color. I mean it had some, but can hardly see it. A practice piece maybe for later. Well, later came and while doing other stuff I just figured why not work on the bad piece, I mean, I CANT hurt it, its bad already. So I went to town (oooh, an Americanism?)(sorry don't know the equivalent Australian) on the bad piece with no visible color. Sanding shaping treating and finally a bit of polishing. Well, it wasn't any skill on my part, but it turned out pretty good. Flashes of red from every angle, even the back. Well, maybe some stubborn persistent Scandinavian effort...lol...
The attached pics do show the color, but its better in hand.
And, it was a great reminder for me that Opal, even matrix opal, can hold unseen surprises, sometimes good surprises. Dont throw away that offcut, it may hold something good.

[SwordfishMining]

They can just scoot the pile over me for an Insta_Cairn of rough around here too. No bright chip is too small, no limbcast is too ugly. LOL

[skywalker753]

The three matrix opals from the single piece of rough. The color in the two is great, looks only ok in the pics, oh well.
Also, I have to sand, re-treat, and re-polish the two good ones. I put my files away in the wrong order last time I used them and didn't check this time, just used them like usual. AND forgot to use lighted magnification between grits/mesh. Didn't get all the scratches out is the result. Didn't even see it until I started sanding off the carbon near the end of the process. Well, live and learn, again...lol...
Its not that long or difficult a process to "fix" them, and I will do it knowing they will just have a better shape and look better in the end this time. Like they should have the first time...

[PinkDiamond]

They're looking great sky, keep up the good work. No opal with color is unworthy of effort to bring out as much color as possible, so good luck on the reworking of them and I hope you uncover even more color.

[skywalker753]

Thanks for the encouragement!
I do wish there were others who were posting about their doing opals by hand, or matrix opal by hand. Maybe there are, and they just don't feel like posting!...lol... Think about it...what if you made, by hand only, a family heirloom, an opal that could be handed down for generations...
But, I digress...
So, I had a fairly large size (for me) matrix opal of about 56 carats, in the rough. After working it the combined 3 matrix opals are about 36 carats now, and I'll be sanding and polishing maybe 4 more carats off of them to get to the final sizes. That a fair bit of wasted matrix opal, but I feel pretty good about the yield. One of the founders of OpalAuctions wrote an article where he said that waste material when cutting matrix opal can approach 80 percent. Maybe he was referring to the just out of the mine rough matrix opal, I'm not sure. But my waste material is just over one third the total weight of the matrix opal I bought. I don't know if thats high, or low, or about right.

[skywalker753]

I did re-sand and re-polish all three matrix opals, and got rid of the scratches. Yea! Bonus' don't often happen to me, about as often as winning the lottery, but they did this time. Three Bonus': One, they have an incrementally more pleasing shape. Two, the color is both a bith brighter and covers more surface area. Three, I didn't need to re-treat them, they look good.
Some of the black color did go away sanding more, but was replaced by a nice looking matrix plenty dark enough to show off the opal. So I left it as is. And if I want to treat it later, I can do that. One word of caution about sanding more to get better color. It CAN go both ways!!! Its happened to me where "just a teensy bit more" becomes, "ah naw, where did the color go, its gone!!!"