juzwuz
has rocks in the head
Member since April 2010
Posts: 526
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Post by juzwuz on Oct 8, 2010 23:10:11 GMT -5
Here's a couple of slabs from a Brazilian agate I got from a local rock show. It's a nice blue color with some neat patterns. It seems like I can only cut two slabs of this agate and then I need to dress the blade. If I don't, the cut stalls out halfway through and things start to get hot. I probably need to get a new blade? Any suggestions for 10" blades? I thought someone recommended a MK3?? (can't remember the number).
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Post by tanyafrench on Oct 9, 2010 6:52:21 GMT -5
I know nothing about blades, but I do know what I like and that blue agate is stupendous. I love the color and the bands. Great stone. Tanya
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Post by Toad on Oct 9, 2010 7:17:04 GMT -5
Lovely slices
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Post by johnjsgems on Oct 9, 2010 8:36:02 GMT -5
Whether artificially colored or not, Brazilian agate is really tough on blades. Frequent dressing is a must. Oil would better than water also and a slow feed rate.
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Post by frane on Oct 9, 2010 8:46:43 GMT -5
That is a beauty too! I would cut a piece of obsidian in between slices of a very hard agate just to keep the blade sharp. Maybe that would help. Fran
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juzwuz
has rocks in the head
Member since April 2010
Posts: 526
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Post by juzwuz on Oct 9, 2010 22:15:06 GMT -5
I got the rock from a bucket of mainly thundereggs mixed with some Brazilian nodules. It's about the size of two fists. It was showing some dark bluish color at the bottom of the rock but I didn't realize that the inside could be that dark intense blue color.
I have a 10" TS-10 Lortone saw with a automatic feed and in order to dress the blade I had to turn off the feed, turn on the saw, reach inside with a piece of fire brick and make a few cuts while trying to avoid an oil bath by holding a shop towel to catch the mist. Not the funnest thing to do but I had to cut some more slabs since my daughters had already claimed these two slabs for their collections.
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juzwuz
has rocks in the head
Member since April 2010
Posts: 526
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Post by juzwuz on Oct 9, 2010 22:18:53 GMT -5
Whether artificially colored or not, Brazilian agate is really tough on blades. Frequent dressing is a must. Oil would better than water also and a slow feed rate. Do you think the color is artificial? I've seen dyed slabs before but never knew how it was done. Can the whole nodule be dyed on the inside somehow? Hopefully this isn't too silly of a question.
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Post by jakesrocks on Oct 9, 2010 22:25:21 GMT -5
I doubt if that one is dyed. Agate is usually dyed after it is slabbed. There is very little chance that dye would penetrate all the way to the center of a nodule. Dye would also show on the outside rind.
Don
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peachfront
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Stones have begun to speak, because an ear is there to hear them.
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Post by peachfront on Oct 10, 2010 17:31:35 GMT -5
It does not look dyed to me either. Material from Brazil has a bad reputation but that isn't the garish shade of fake blue I've seen in dyed-blue Brazilian agate. We have certainly cut open Brazilian agate nodules before and found similar color, although your specimen is pretty durn special! Google a bit, and you'll come up with plenty of photos of sellers offering the dyed material. Your tasteful but well-marked piece is just not in the same category in my humble opinion.
I actually like the dyed-green agate and purchased a pair of "jade" beads that is clearly dyed-green Brazilian agate for my personal wear but the dyed blue and pink stuff is just a horror.
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redrummd
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Post by redrummd on Oct 10, 2010 19:09:19 GMT -5
Oksy before I ask my question I want all to know I am serious and mean absolutly nothing negative - I just want to know.
I can't see any blue in this and many other stones people refer to as blue. I see a pale greyish color that is translucent. I could describe it as a slightly blueish grey.
So, when you say it it blue do you see it as really blue or as a really almost wishful slightly blueish grey and call it "blue" due to the VERY slight bluish tint?
I am asking as I honestly wonder if I am slightly color blind and just don't see the blue that others can see.
Honestly, I really just want to know and mean absolutely nothing negative....
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Post by deb193redux on Oct 10, 2010 20:34:55 GMT -5
Blue in agate is generallly never as blue as in sodalite or lapis or dummerite. But there is grayish-blue and bluish-gray. I would say these were very blusih-gray.
I have one half-nodule where the blue seems even darker. In a few days I might be able to scan it and put up a pic.
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Post by johnjsgems on Oct 10, 2010 20:51:53 GMT -5
I see blue. Maybe not as awful as the typical wind chimes and book ends but blue enough to suspect some heat or chemical/salts treatment. I could be wrong but most untreated Brazilian I've seen is pretty pale.
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Post by deb193redux on Oct 10, 2010 20:57:14 GMT -5
Chemical treetments seldom penetrate too deep into the stone. Heat usually make things red'er.
The juxtoposition with the peach color makes me think this could be natural.
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peachfront
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Post by peachfront on Oct 10, 2010 21:32:52 GMT -5
Redrummd...it is blue-gray, and some people would definitely call it grey, while I (and some others) might tend to call it blue. But, I'll be honest, this Brazil stuff photographs "bluer" than it looks in person. Do you know how some people have what we call, on our driver's license, "blue" eyes? But if it wasn't the person's eyes, if it was a stone, we would call it gray? That's the shade of blue we're talking about in these Brazilian agates. I read a few years ago that it's a matter of class/where you came from in the South if you call that color "blue" or "gray." I have had the same color (my eyes) called either depending on who was working that day at the Department of Motor Vehicles, and then for the next four years my eyes were blue or my eyes were gray. But they were the same pair of eyes You are not color blind, this is just a borderline color, and our language for describing color isn't too accurate.
I am not going to get involved in a debate on what is grayish-blue and what is blueish-gray. I have no idea what possible difference there could be between the two. I honestly think we're all seeing the same thing and it depends on cultural background what we call it.
To johnsgems-- it's my understanding that heat treatment makes the stone more orange or red, not more blue. I have a recipe for heat treating Brazil agate in any home oven, and it clearly intends for me to make the stones redder/more carnelian like -- NOT bluer. But I have not got off my duff and tested the recipe. Maybe it's time. I can't do it this month but I'll be highly tempted to do it at some point before the year's end. Based on other reports, though, I would not expect heat treatment to make the stones bluer. If it does, I'll be all over that.
Either way, when I do the test, I'll make a full report.
To deb-- I agree. Hard for me to see any way that the stone could be heat/chemical treated without impacting the peach banding. Seems like it would be significantly darker. The subtle yet well defined nature of this piece really argues heavily for a natural stone as far as I'm concerned...not that I'm any expert. Far from it. But I would need to have an explanation of how this stone was treated so precisely.
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Post by deb193redux on Oct 10, 2010 22:35:00 GMT -5
.... what is grayish-blue and what is blueish-gray. I have no idea what possible difference there could be between the two. ... Peach, in adjective-noun pairs, the noun is the thing itself, and the adjective qualifies it. SO bluish-gray is a gray, but the the blue-gray aspect versus greenish-gray, or dark-gray, ... etc is highlighted. Grayish-blue is a blue thing,. but as opposed to royal blue, or sky blue, the grayish nature is highlighted. If you think about it, I shure you will realize you do know the difference between a grayish shade of BLUE and a bluish shade of GRAY. www.artfire.com/modules.php?ame=Shop&op=listing&product_id=1987324The one in this link has blue and pale peach, but the blue does not look natural, I think the slab was dyed after cutting The one below looks natural, but it is lighter blue: www.spiritrockshop.com/images/Agates_016.JPGBelow is a link to other types of blue agateL www.glypticconcepts.com/AboutBC.htmlThis one has very dark blue, but also seems natural: www.quartzpage.de/px/ag_br_brazil_Q316_1_scl.jpg
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peachfront
fully equipped rock polisher
Stones have begun to speak, because an ear is there to hear them.
Member since August 2010
Posts: 1,745
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Post by peachfront on Oct 11, 2010 22:06:34 GMT -5
Deb, maybe I'm the one who's color blind but nope...just don't get it. Great links though! I'm still drooling over the one from spiritrockshop,com...what beautiful markings.
Kinda sad maybe that I can't tell blueish gray from grayish blue or whatever, because I actually took a lot of art courses. I had the same problem with some of the yellows. I could see that they were different colors, sure, but I couldn't ever figure out why one of them was considered yellow-green and another would be greenish-yellow, to me, they were all in the same category.
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Post by johnjsgems on Oct 12, 2010 12:09:56 GMT -5
I meant no offense. I am a pessimist by nature. So many rocks are heated, radiated, chemically, enhanced, etc. now days when I see a truly beautiful rock like this I have to wonder. Most "carnelian" marketed today is indeed heated agate. Rock & Gem magazine had an interesting article a while back on various chemical salt mixtures used to color agate. Radiation is used to enhance colors as well. I have seen pretty nice agate banding around the amethyst cathedrals so no reason the nodules can't be real too. Especially if it is less blue than pictured.
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juzwuz
has rocks in the head
Member since April 2010
Posts: 526
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Post by juzwuz on Oct 12, 2010 15:08:16 GMT -5
No offense taken. I'm a newbie rockhound but always curious engineer so I like to try and figure things out. On the outside, the rock is ordinary except there are a few windows on the ends which show a dark color. When I cut the end off, it showed the nice blue color. It's definitely not as gaudy as some of those blue dyed agates but it's quite blue....to me it's grayish-blue. The next two slabs are in the first post of this thread. I managed to get another slab which I haven't taken a picture yet. The next slab is halfway done but again the blade has stalled out so I need to wait for tonight to dress the blade again. I think I can get one or two more slabs before I have to take the rock out of the vise and then I'll take some more pictures.
Maybe my camera colors are off but I've stared at the slabs and pictures and the colors seem pretty close. Maybe I'll try scanning a slab?
It would be interesting if someone figured out how to dye/heat treat an uncut rock all the way through the middle.
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Post by jakesrocks on Oct 14, 2010 22:19:48 GMT -5
Don't know if the rock is picking up some of the saws color, but I see bands ranging from light blue all the way up to gray blue. Even the white in the center seems to have a slight blue cast. Beautiful piece. Guess I'll have to cut some Brazilians, and see what I have.
Don
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