mjflinty
spending too much on rocks
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Post by mjflinty on Nov 20, 2012 8:56:34 GMT -5
Great pieces!
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mjflinty
spending too much on rocks
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Post by mjflinty on Nov 20, 2012 8:48:09 GMT -5
Thank you everyone for the good words. I started out in lapidary in Ohio, so I tend to gravitate to Flint Ridge Flint. The flint deposit has just about every color and combination you can imagine... toughest part is getting it all in one slab that is cab sized!
Michael
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mjflinty
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Post by mjflinty on Nov 19, 2012 21:12:45 GMT -5
Still available...
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mjflinty
spending too much on rocks
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Post by mjflinty on Nov 19, 2012 16:42:30 GMT -5
Hi All, I ordered the wrong wheel on eBay and didn't realize it until it was too late to return it. It's a 4" x 1-1/2" Diamond Grinding Wheel 80 grit that fits a 1" arbor. I have hole size adapters that will allow the wheel to fit on 1/2", 5/8" or 3/4" arbors and can include them with the grinding wheel. I'd like to get $50 or trade it for some slabs. I'll cover the shipping too. Here are some pics: www.rockhobbies.com/images/products/1353361039m95b.jpgPM me if interested. Thanks, Michael
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mjflinty
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Post by mjflinty on Nov 19, 2012 12:28:30 GMT -5
Hi All, I finished up some new wraps. These are all Ohio Flint Ridge Flint cabs that I cut, polished and wrapped. Thanks for looking, Michael
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mjflinty
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Post by mjflinty on Nov 13, 2012 13:32:50 GMT -5
Very well done! I like the minimal use of wire and focus on the stone :-)
Michael
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mjflinty
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Post by mjflinty on Nov 12, 2012 18:33:56 GMT -5
Cool stuff! Looks like I'm finding some of the same material out on the gravel bar.
Michael
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mjflinty
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Post by mjflinty on Nov 12, 2012 16:16:02 GMT -5
Looks like you are coming along! Your percussion work is pretty clean overall, might abrade a bit more to help with step fractures. Texas rock can be tough when it's raw, a little heat treatment can make it gloss up and chip easier.
Michael
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mjflinty
spending too much on rocks
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Post by mjflinty on Nov 12, 2012 8:40:54 GMT -5
Dolphite with Opalite cortex :-)
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mjflinty
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Post by mjflinty on Nov 11, 2012 16:59:32 GMT -5
I have a little more left. Now that I know it'll take a polish I'm going to cab the rest.
Michael
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mjflinty
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Post by mjflinty on Nov 8, 2012 8:52:40 GMT -5
Hi All, I friend of mine sent me some stone he collected from a quarry in New York state. I think it is some sort of seam chert as the host matrix is limestone. I have never seen anything like this and would love to be able to put a name on it. Upon close inspection I see very small seams of silver running thru the stone perpendicular to the black lines. Any ideas? As you can see it took a great polish in the vibe. Thanks, Michael Attachments:
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mjflinty
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Post by mjflinty on Nov 7, 2012 11:42:15 GMT -5
I'm in Alton. Have you checked out the gravel bar at Chain of Rocks? It's one of my favorite places to hunt and there is lots of agate!
Michael
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mjflinty
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Post by mjflinty on Nov 6, 2012 8:52:53 GMT -5
no worries, maybe next time...
Michael
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mjflinty
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Post by mjflinty on Nov 4, 2012 10:25:48 GMT -5
That's a great batch! Liking that 9th laker too!
Michael
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mjflinty
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Post by mjflinty on Nov 3, 2012 20:58:22 GMT -5
I'm interested. Any guess on shipping? Do they fit in one flat rate box?
Thanks, Michael
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mjflinty
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Post by mjflinty on Oct 31, 2012 18:01:42 GMT -5
Excellent! Thank you so much for the link! Look forward to seeing some awesome cabs!
Michael
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mjflinty
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Post by mjflinty on Oct 31, 2012 11:59:54 GMT -5
Hi All, I'm wondering if anyone could offer some advice on my grinder. I purchased it about 15 years ago from Lopacki diamond tools. Since then they have stopped selling replacement wheels for it. The wheel size is 4" X 1 1/2 X 1/2. I've googled all over for it and can find the machine listed for sale on a Chinese website but, no wheels for it. I'd like to get a new 60 grit for it. Any ideas? :help: Thank you, Michael Attachments:
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mjflinty
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Post by mjflinty on Oct 31, 2012 7:46:30 GMT -5
I can't say I've ever heated amethyst... it's not something that would have improved knapability seeing that it is just silica.
I'm certainly curious what would happen if it was heated. I recall from my geology classes that the amethyst color develops due to heat; if it gets really hot it turns to citrine (I think).
Michael
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mjflinty
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Post by mjflinty on Oct 30, 2012 15:31:22 GMT -5
As a knapper I heat treat chert, jasper and agate often. The main goal is the same... to make the stone easier to chip. The bonus for most materials is a higher gloss when chipped, color change, and more control over the conchoidal fracture. I wear an archaeologist hat during the day so I can tell you exactly what happens to the stone when it is heated too; the stone undergoes a sort of "recrystallization" process, the material surrounding the silica grains (called flux) will basically melt. The melting of the flux causes oxidation so, browns becomes reds and any air space will be gone leading to the higher gloss. Humans figured all this out about 20,000 years ago.
As a lapidary, I have worked lots of material that I heated for knapping. The only noticeable thing will be a reduction in the strength of the stone... it will grind away faster. This is true for heated stone knives too... the edges wears faster than raw rock.
Over heating stone is very possible. You can heat it too quickly and it will explode. The water molecules in the stone will get very excited and cause "pot lids" to come flying off the surface of the stone. If the stone gradually gets way too hot it will go beyond heat treated to what we call crazed. Crazed rock is gravel, it has lost all of its internal structure and if full of micro fractures.
Most siliceous rocks will heat in the 350 to 500 degree range. The best results will come from a gradual heating; I like to start them at 250 for an hour and then raise the temp 50 degrees per hour till I reach my max temp. Then I hold that temp for 4-5 hours. The stone will need to cool down gradually too. Let it sit in the roaster for at least 8 hours or till the sand is cool to touch. If they cool too quick you can get crazed and nobody wants that.
Keep on experimenting! Michael
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mjflinty
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Post by mjflinty on Oct 18, 2012 8:22:41 GMT -5
Ok, I'll PM you some contact info. I have a friend back in Ohio that sells lots of rough with good color.
Michael
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