Joined: Wed Sep 02, 2015 10:52 pm Posts: 1131 Location: Central Queensland, Australia
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Gentlemen, I'd say the swap went quite well! Next time I would encourage more swappers to participate. For the few $$ it took to ship a pound around the world, it was more than worth the effort.
Agreed! I now have some great specimens, hand-collected by the person who sent them, from parts of the world I may never have time to visit during my life. If my mate brings out the rock saw he was recently given, I'll run a bunch of Mount Hay thundereggs through, got about a half a 5-gallon pail of little posting-sized ones.
Sorry to hear about your mica Shifter. Mine survived well. It's one of the coolest-looking specimens in the box I reckon. When I peeled the bandage off I first thought it was a piece of quartz. Then I saw the crystal shape and realized that it was something else, quartz crystal doesn't look like that.
A couple of the sapphires I sent should be facetable, though they will be small. I'll put the ones you sent me in the display case with their origin labelled - sapphires are bloody rare, rarer than diamonds geologically I believe (Stephen can confirm/refute this?) and if you have some it's good to know where they came from.
The rock swap was a great idea Dan Long may it continue.
Gentlemen, I'd say the swap went quite well! Next time I would encourage more swappers to participate.
I can definitely agree to that! Maybe in a couple of months I'll put up some more stuff to swap as decent Australian stuff tends to slowly appear and it gives me time to decide on other things that I have that are worth sending.
And eh, it's mica Lefty, unless you are careful with every aspect of transport from ground to dop removal good crystals will break. I don't expect or want other people to put that sort of effort in it because it isn't really worth the solid book you get. At least I don't have to worry about cleaving it myself and breaking it badly with pliers. If I can figure out how to reinforce it adequately I might try cutting some beveled windows to send, otherwise it is hand-cabbing for this stuff, the iridescence that will inevitably appear from the stress of cutting will be nice.
Joined: Wed Jan 14, 2015 3:52 pm Posts: 576 Location: N Dakota
I have peeled mica into sheets so thin I could wrap a coke can without it breaking apart. It is definitely an odd character and the rainbows are like an oil slick on water. I have no earthy clue how you would facet it or how you could keep it in one piece.
Joined: Wed Jan 14, 2015 3:52 pm Posts: 576 Location: N Dakota
I was looking in to heat treating some of my flint and agate for my friends here that Knapp arrowheads and such. It appears to be a simple process using a turkey roasting pan. After reading several opinions and watching multiple videos, it's a simple deal. Two hard and fast rules. Dry it out first, ramp up the heat slowly and cool slowly. There are charts for temperature ranges for many types of rocks. Of interest to me was the KRF and Montana agate. KRF is max 350° and agate 450° - 500° with a ramp of 50° per hour. Pack your roaster with sand and monitor your temperature hot spots so as not to exceed the limits of the stone. The objective is to get a more workable stone with a glossier appearance. By workable I mean more easily flaked with billet strikes and pressure flaking. For cabbing it may soften the stone some or intensify the colors some. Something to think about for agate maybe.
Joined: Tue Jul 02, 2013 9:00 am Posts: 1322 Location: Wylie Texas but in Alaska for a while
These days you can pick up a programable controller that could control the rise and fall times pretty cheaply (if i remember right in the $20/30 range. With it you could use your sand packed pan and an electric frying pan ($10 at a thrift shop)
The ones i saw actualy had a learning curve on them and they learned the overshoot and adjusted.
It would make the proces easy once it is set up.
I know that you also plan to get what you need to cast ypur own jewlery. A programable burn out furnace would easily do it. You could set rise and fall to as little ad a few degres per hour. Might be worth starting to look put for one.
If you were close to dalas i would say drop by and use mine. I recently used for something odd so i know it is working. It is 110 volts so i can set it outside under the patio and kep heat and the oddsmell out of the house, and the wife happier
Joined: Wed Jan 14, 2015 3:52 pm Posts: 576 Location: N Dakota
Should be able to find a programmable controller to hook up to the crock pot thing too. Ok so how would that work? Use a thermal coupler or just a thermostat. Or both, one to monitor temps and the other to turn the elements on and off. Splbbttt. I'll just see if I can find one , don't feel much like building circuit boards. Anything I remember how to work with left just after tubes and black and white TV's.
Joined: Wed Sep 02, 2015 10:52 pm Posts: 1131 Location: Central Queensland, Australia
You definitely have to heat slowly and cool slowly Dan. I tried it a while ago with some of my Fitzroy river agate and while it did intensify the colour - quite dramatically with a couple of the pieces - I think I cooled them too quickly and many of them cracked.
A programmable set up like Wilson suggests would be the go for nice, even heating and cooling.
I'ld be careful to remove all of the ironstone and cracks in that agate before you try to heat it, given the metallic tone in the matrix. Hopefully it doesn't turn all the yellow layers red like what happens to Tiger's Eye.
Also I suppose the heat treatment anneals the agate and might even change the crystal structure somewhat? Given that I sometimes have to be careful with the saw as it can produce "tearing" marks in agates the grain structure must be very hard to deal with when knapping.
Last edited by Shifter55 on Tue Jun 28, 2016 4:36 am, edited 1 time in total.
Joined: Tue Jul 02, 2013 9:00 am Posts: 1322 Location: Wylie Texas but in Alaska for a while
I have to correct myself. It looks like low priced "PID" will hold a temp (for as little ad $14 (US) But it will not do a ramp.
To control ramps you need a programmable model, this about $80 that can be programmed with up to 50 segments including risetime whole time and full-time.
There may be cheaper ones out there but this is the first one I came across.
They usually have a SCR output that can be used to control of up to 40 A that should let you handle almost anything we would need for the skill of work were doing
Joined: Wed Sep 02, 2015 10:52 pm Posts: 1131 Location: Central Queensland, Australia
Yellowstone river agate and Knife river flint, courtesy of Dan...
Even though the agate is clearly the exact same type as I pick up on the river crossing, I have only ever found a small handful of pieces where the colour goes right through like this stuff does. Mine is usually disappointing, brilliant orange outside but nearly always milky white by the time you get in about a millimetre.
Wouldn't mind some more of the agate in a future rock swap, especially the banded stuff
Joined: Wed Jan 14, 2015 3:52 pm Posts: 576 Location: N Dakota
oh I dont think it will be a problem. I seem to have the same problem you do, with barrels of the stuff. I just cant leave it on the ground. So my pockets fill up at work and my lunch pail then the shelf. Rocks everywhere! Good thing we dont live in earth quake country or I might be buried alive in my own garage With any luck Timur will be down again in the fall he can help me sort out some better quality materials for the swap. The KRF supposedly turns a lighter red when its heated. I had a nice bird point like that i had found here. It killed many grouse until it found a rock on the pass through and turned to dust.
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