Tommy
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Post by Tommy on Dec 14, 2013 22:54:59 GMT -5
Here's what I know for sure - it's black or very dark green, with a shimmering lighter green running through it, smooth and rounded on the outside, and harder than steel. Main boulder weighs around 50+lbs... it's a stunningly beautiful rock. The person I was dealing with didn't know what it was and didn't want to sell it, but later indicated they might take $100 for it. I bought a 10lb end cap off the same boulder - not as colorful as the main rock but I wanted to positively ID it before plunking down $100 (assuming it's still available). Smooth and rounded exterior -
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Sabre52
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Post by Sabre52 on Dec 14, 2013 23:34:55 GMT -5
Does look a lot like nephrite in the pic. Really has the look of some of the material from Darrington, WA and the WA stuff often comes in cobbles rather than slicks.....Mel
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Tommy
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Post by Tommy on Dec 15, 2013 15:10:18 GMT -5
The plot thickens ... I was able to whack the end off and make a few slabs today and I learned some things in the process. First thing is that it's not black at all, it's dark green and transparent... Second thing is that it's loaded with some sort of metallic looking inclusions that I didn't see yesterday. I measured the specific gravity of 5 different pieces ... if I'm doing this right I came up with the following readings 2.66, 2.68, 2.65, 2.67, 2.62 for an average of 2.656. Too low to be Nephrite yes? I already knew it was harder than steel but here's the evidence anyway... Thoughts or ideas are welcome, thanks.
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Sabre52
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Post by Sabre52 on Dec 15, 2013 19:27:20 GMT -5
Yep specific gravity for nephrite is usually like 2.9-3.0 or so. That being said, your slabs really look like nephrite, hardness matches, and nephrite is often loaded with inclusions or crystals of metallic magnetite like your example is. Your specific gravity is dead on for serpentine and it often has the magnetite and look of nephrite. Some real good serpentine almost reaches nephrite in hardness ( 4.5 or a bit higher). Some steel is pretty soft. Will hard steel like a file scratch your slabs? ( file is usually over mohs 6). Might be a real gemmy hard example of serpentine but the hardness sure seems like jade......Mel
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Tommy
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Post by Tommy on Dec 15, 2013 19:54:04 GMT -5
Some steel is pretty soft. Will hard steel like a file scratch your slabs? Wow, how do you do it Mel? heehee. Like I said yesterday, my education continues every day. I tried the scratch again with a file and a drill bit and both scratch it easily... So I guess serpentine it is yes?
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Sabre52
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Post by Sabre52 on Dec 15, 2013 21:11:54 GMT -5
*L* Sorry Tommy, I was kind of thinking out loud and my comments could have been a bit misleading. Nephrite jade is mohs 6-6.5. File steel is about 6-6.5. So a harder file might scratch softer nephrite or a softer file might not scratch harder nephrite. So, that test can have varying results and be not so clear, However, the specific gravity and the fact that your initial scratch test was softer steel makes me think you have a real hard example of serpentine. When I used to dig jade up at Porterville, CA, some of the serpentine was almost a jade intergrade and was quite hard and could not be scratched by a common nail ( mohs 5-5.5) but was not true nephrite jade......Mel
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Sabre52
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Post by Sabre52 on Dec 15, 2013 21:21:33 GMT -5
Tommy, You might try the famed ring test too. If you lightlly tap a nephrite cobble with your hammer, it should ring or clink almost like a bell. Serpentine is usually more of a clunk or thud *L*. We actually hunted nephrite lenses which were often vertically bedded by going along the hill banging the rocks with our hammer. If you went thump, thump, boing!, the boing or clang or clink was a jade lens. A fairly metallic sound to the jade when struck.....Mel
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Tommy
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Post by Tommy on Dec 16, 2013 0:19:27 GMT -5
Tommy, You might try the famed ring test too. If you lightlly tap a nephrite cobble with your hammer, it should ring or clink almost like a bell. Serpentine is usually more of a clunk or thud *L*. We actually hunted nephrite lenses which were often vertically bedded by going along the hill banging the rocks with our hammer. If you went thump, thump, boing!, the boing or clang or clink was a jade lens. A fairly metallic sound to the jade when struck.....Mel Haha I was just telling the missus over dinner that that was one of the first things I tried today when I got a slab cut. I dinged it against a few hard surfaces and it definitely did not *ding* like a windchime as I have read that Jade will. More of dull thud like you described...still I held out hope I guess haha. I didn't try dinging the cobble itself - I'll try that tomorrow. Thanks for all your help!
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Deleted
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Post by Deleted on Dec 16, 2013 17:16:23 GMT -5
gorgeous serpentine is just as good for your purpose as jade.
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Tommy
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Post by Tommy on Dec 16, 2013 19:17:43 GMT -5
Yeah maybe, except I thought I had found that once-in-a-lifetime rock... lol j/k. Honestly jade or serpentine I'm not that thrilled about making cabs from a dark (black) material laden with magnetite...I think it will darken even more upon polishing but I'll try one soon just to see how it looks. Maybe a pendant with an LED backlight shining through the green hahaha.
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Post by Pat on Dec 16, 2013 19:23:26 GMT -5
Whichever it is , it's very attractive. As earrings set in a stepped bezel, the light could come through.
Very pretty slab!
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Sabre52
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Post by Sabre52 on Dec 16, 2013 19:50:02 GMT -5
Yeah, those areas of magnetite can be heart breakers due to undercutting. Porterville Jade I've worked is often full of it so you have to pick and choose your areas to cab very carefully. Sometimes you get flecks of bright green which may be chromium. Those don't undercut so make real nice pieces. There is a solid translucent green type of serpentine that is really awesome stuff too.....Mel
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