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Post by kk on May 13, 2012 4:28:00 GMT -5
Found something interesting, but have no idea as to what it is. Last week yielded 3 different materials that actually take a good polish The one in the middle seems very much like the one seen in the picture of the Swedish Odd-Ball Quarzite. Polishes ok, but I'm not too keen on the colors. The second one is a mixture of two distinctive materials. Tries to undercut, but polishes up very well. As I had so many materials that did not finish well, I did not bother to cut it from the rest of the stone. Will have to do that next. And then there is that rather strange one. I’m looking already the whole week all over the internet, trying to find out what it is but nothing seems to completely fit. My guess is diopside, but there are things that do not seem to match. I found it in a seam in a granite face. Was underwater yesterday upon my return. Hard to get a solid face as a lot of material has been leached out by nature over time. This is an example of another seam that yielded very different material and is relatively easy to access. First surprise: metal flecks throughout this particular piece (but not interconnected) I guess that those metallic inclusions are the reason for it to be pretty dirty to work with. By far not as bad as Phsilomaine, but still. Second surprise: too dark to see anything under the surface, yet at times looks like it has depth. Third surprise: indication of asterism. At places light does not seem to penetrate at all, at others the light penetrates but is reflected back out in other places. Both are observed; slight 4 star (very small) and again very light cats eye. I suppose I cut it the wrong way. Polishes up as good as it gets But shows a lot of cracks under magnification So regardless to what it turns out to be, I’m on cloud 7 finally having found something that really polishes up and looks good. Last one to bother you with is yet another seam that yielded something very similar to Phsilomaine minus the ring-growths. Just as dirty to work with. The seam And the face ground flat Thanks for your time, and I would be grateful of getting any hint as to the ID of the black one..... Have a great weekend everyone and Happy Mothers-day to all the mothers out there. hatsoff14 hugs23
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Post by kk on May 13, 2012 17:37:59 GMT -5
What? No-one hazards any guess as to what the black material with the Pyrite (?) flecks could be ?
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Post by gr on May 13, 2012 18:07:46 GMT -5
will a magnet stick to it? looks like silver!
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Post by kk on May 13, 2012 21:39:32 GMT -5
Silver in the last two pictures or the ones before that? Could be, as till about 100 years ago, silver was mined just about 7 miles from that waterfront.
Magnets have no effect. Tried already.
The black one might be slate interspersed with something thayt allows it to be polished up and the inclusions I presume to be Pyrite.
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Post by helens on May 13, 2012 21:50:50 GMT -5
I'm no rock expert, but looking at the pix, my first thought was Basalt. I don't know why. So I looked up basalt online, and it appears that it is formed in many configurations and therefore hardnesses? Some are highly silicated (glass is mostly silica), which would make it shine well? Consider that carbon can be soft as coal or diamonds, compression makes a difference in what something ends up like hardness-wise. Anyway, here's a wiki, what do you think? en.wikipedia.org/wiki/Basalt
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Post by kk on May 13, 2012 22:48:39 GMT -5
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Post by Deleted on May 13, 2012 23:05:37 GMT -5
Get a geologist and a chemist interested and they can probably figure it out or send some to a university that teaches rockology. If the silver area is mica you should be able to pick it loose in thin layers and I think it is too soft to polish and would under cut like crazy. There is a lot of mica in the rocks around here and when you scratch it it crumbles into something like dirt. Jim
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Post by helens on May 14, 2012 2:08:32 GMT -5
Well, with as many jewelers as there are in HK, can't you ask one to do a simple silver test on an exposed silver part of the rock (they drop some chem on it and see if it change colors)? It actually DOES look like silver flakes judging by the photos of silver nuggets online. If it IS silver... you can't get it out of the rock anyway... BUT, I'd think it'd be as valuable in terms of silver prices as gold in quartz is to gold prices. I just randomly looked up a site with prices for you already made into jewelry: www.alaskajewelry.com/gold-quartz-jewelry-pendants-c-124_198.html?osCsid=24abe4a6f96383bcadb9cc9e095ad770They don't pick the gold out of the quartz... they just weigh the whole thing and charge gold prices it looks like. Current gold/silver spot prices: $1576.60, and silver is $28.86 (yes, precious metals are crashing). I found no references to silver in rocks... so IF that's silver... you might be able to create a whole market for it:).
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Post by helens on May 14, 2012 2:21:22 GMT -5
Oh, on the basalt part, did you look at your link for the section on 'pillows'? If the basalt forms UNDER the water (and wasn't Lantau created by volcanic activity like Hawaii?? It looks like from all the mountains and jagged peaks everywhere), it says that it would have a very fine grained core with a glassy crust. While your photos don't look like pillows of any kind, point was that basalt can form very dense (polishable) rocks as well as fluffy volcanic ash. Any chance you can bring a snorkel with you next time and peek in the water to see if there are any 'pillows' in shallow areas with some visibility? If it IS basalt, then you may have little round polishable pillows in the water too:).
It looks from your pix like the seam was formed from SMASHING 2 sides together very violently, and thus created a ridge of extremely dense materials? I don't know much about geology, but it just seems logical to me that it's possible, since we know that many of the best gems are found in 'veins'. And extreme high pressure would create the densest materials from compression.
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Post by helens on May 14, 2012 2:26:25 GMT -5
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Post by kk on May 14, 2012 6:01:14 GMT -5
But seriously... given how many people have been all over lantau, if there was silver there... wouldn't they have found it by now? I'm still voting for basalt:P Actually, we know that silver was mined for over a thousand years here on the Island. The last mine shut down in 1906. I dont think its silver either. removed some of the backing material and suddenly the whole vain sticks to a magnet. I'm in process to polish one fragment up and it seems to have a nice Blue/gray color. Whatever it is; if it polishes up like Phsilomelaine, then I want more.
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Post by kk on May 14, 2012 9:53:02 GMT -5
Just found a road-map of known mineral deposits here in Hong Kong, and it looks like its going to be narrowed down to (last two pictures) Graphite, Tungsten or Lead which are all recorded within 10 miles from the location I found it in.
Will be writing to the website, and hope they can give definite answers.
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Post by Deleted on May 14, 2012 13:46:46 GMT -5
I was under the impression that tungsten is man made and lead does not stick to a magnet. I am not sure about graphite. Magnetite looks silvery when polished but not as silvery as what yours looks like. Jim
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Post by kk on May 14, 2012 17:09:25 GMT -5
We got Magnetite too within Hong Kong. Actually had it mined during the Japanese occupation.
Will see if the guy from the "Geo Survey" website answers. Would be fun if they would want to do a site inspection. Could learn a lot from that.
In the meantime I already found out that the site where I found it has 400 mil. years old bluff, with 140 mil years old volcanic eruption interspersed.
So, in the moment, its anyone's guess........
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Post by helens on May 14, 2012 20:09:29 GMT -5
Well, your stuff looks sort of like some Phsilomelaine pix, but not with the big silver flecks in it... if it is, it would be a new type. Either way, it's great new stuff that's not already much on the market:).
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Post by kk on May 16, 2012 5:29:57 GMT -5
I contacted our Geological Institute here in Hong Kong with pictures of the material, and they where friendly enough to actually answer me back. The first was a very general answer most likely written out of courtesy by a secretary as seen below: "Quote" Thank you for your inquiry. Iron (pyrite), tungsten (wolframite), and molybdenum mineralization is known from Lantau, particularly in western Lantau from Tung Chung to Yi O. Minor lead mineralization (galena) is also known from Silvermine Bay, where tiny amounts silver were found associated with the lead minerals. Graphite seams are also known from the western part of Lantau, and commonly contain pyrite mineralization, and sometimes marcasite (white iron pyrite), and magnetite (black magnetic iron mineral). It appears from your photos that your specimens are pyrite minerals associated with graphite seams. I suspect they have been collected along the coast between Tung Chung and Tai O. There is a skarn deposit with some garnet also present at San Shek Wan, along with some magnetite. "End of Quote" But then I told them that they where death wrong in regards to location (all locations mentioned are in the northern part of the island) and suddenly I got an email from the boss yesterday asking me for a map with general location. LOL Now, today, they are asking for a sample and I might just about give them one, but not before I go back to get more of it. LOL Whatever it is, it does not take a shine like the Phsilomelaine as I was hoping for, I only managed pearly luster, but boy ohhh boy I find that blue/grey color soooooo sexy. saved12 If it holds up to it, I could think of several projects for carving. Here is the first test-sample, up to 2000 grid on sanding-paper and showing closeup of how it breaks. Best regards, and continued suggestions on ID is highly welcome.
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Post by helens on May 16, 2012 6:29:01 GMT -5
The more I look at that, the more it looks like my agatized coral. I won a piece at the local club for a door prize, and it's the weirdest hardest stuff I've ever seen. I would swear it was a 9 MOH the way it does not cut with the diamond wheel. It takes FOREVER to shave a hair off it, and remember I told you about the dremel 'skipping' ages ago because the stuff would NOT cut with diamond dremel bits well either? How hard is your stuff? Highly unlikely its the same stuff, but doesn't it look just like it?? Here's another pix... the holes are full of grit... this is what happened to it after tumbling at 500 grit for a week... almost nothing (see the dremel cuts). The stuff appears harder than the SiC grit, it didn't do ANYTHING to it after a week, other than make a few scratches on the surface. I know it's not possible, but if I based hardness on a scratch test, this stuff appears to be a 9-9.5. LOL!
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Post by kk on May 16, 2012 6:57:34 GMT -5
Nahh, my stuff is actual metal. Its brittle and I would hazard a guess of about the hardness of steel.
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Post by NatureNut on May 16, 2012 8:11:35 GMT -5
Have you tested to see if it is magnetic? Hold a strong magnet up to it and see what happens. Jo
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Post by kk on May 16, 2012 8:22:12 GMT -5
Fridge magnet sticks. So it certainly is not graphite (or at least not pure.
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