Welcome to opalholicsanonymous.com where opal season lasts forever.

Nice pics. Raw beauty there.

So far I sliced that matrix, started working the bit smaller rectangle, and am saving the other one for a rainy day.

Just rounded the edges front and back, took it to 1500, and now its sitting in the sugar for a while. Color shows up a bit better now front and back, but its not polished yet.
I always have high hopes...lol...

Part of quite a few that I do have an "experiment" aspect to them. This one does too. IF it holds together through carbonization, I wanted to see what the visual effect is with all the crevices and dips in the surface that will remain, even after polishing. Those parts should be black,without obscuring the color, and maybe add a nice look, but I never really know til its done. We'll see...

And I had every intention of making a full Cab this time...lol... sometimes not wanting to "waste" material gets the better of me...

I do have a lot of polished slabs or chips, that is for sure.

So, a few sentences about diamond files. Well, this is for people who are doing matrix opal by hand, and using sandpaper. OK, so anyways I did matrix opal with sandpapers (wet/dry) only for a while. Works fine. Takes a looong time. I got a set of flat diamond files, and the process speeded up by lots. Or put another way, you can do a piece in about 40 percent of the time it takes for sandpaper alone. Even using the same grits. I use both sandpaper and diamond files now, its a good combination.
And the diamond files are fairly inexpensive, and last a fairly long time. I mean, a sheet of whatever grit sandpaper will be mostly done after maybe two matrix opals, whereas the diamond files have not worn out yet. Get some! (sure the files will wear out, they're not magic, just good!!!...lol...)
OK, one CAUTION with diamond files. They can tend to cause scratches from the edges of the files moving on the matrix. Watch your pressure, and the edges so they don't gouge, and it will be a great tool.
Just keep your diamond files in order, when you put them away. They look the same (mine do). They are NOT the same grit. In other words, if you want to use a 400 file, make sure its the 400 file, and not the 150 file.....don't ask me how I know this...lol...

LOL, ok, we won't ask.

I haven't got a set of diamond files, but then, I haven't cut any boulder opals. About how much does a set run, and how many are in the set? I figure I'm probably not the only one who's curious.

I got mine on Amazon, and they go from 40 to 600 grit. You can get a lot of different variations in grit, flat or round, etc... The whole set was less than 10 dollars US. Well just under 16 dollars with tax and shipping. Mine are flat with a red plastic handle grip.
There's lots of choices....
But like I referenced above, they LOOK THE SAME!!! (at least my set does) Arrrghhhh....flashbacks!....lol... you can feel with your finger the difference in grit of course but thats not a worry if you put them back in the plastic case in order.....
So, if you search diamond needle file set that should pop up with lots of choices.

The latest matrix opal made it out of carbonization fine, but I ground down one corner (the upper right one) because it just didn't look solid to me.
So, I sanded and pre-polished again, and now overnight in the sugar solution, and recarbonize and polish tomorrow. Thought it would be ready, its not, sorry about that. Should be tomorrow, I think.