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Post by buckshot on Dec 6, 2011 20:12:59 GMT -5
I've located a pegmatite vein on the farm this summer and it is a little hard to get to, my question is to you who have experience in finding pockets in veins. Is there any clue as to whether a Pegmatite may have a pocket with gems before you spend a lot of time digging ? This particular vein is very weathered and soft in a red clay bank. If you have any knowledge that would help, let me know before I shift my emphasis away from looking for rubies, I would like to find an emerald, I'm under the impression that they are sometimes found in pockets in pegmatite as well as other gems, if I'm wrong on this thinking tell me.
thanks,
Buckshot
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Post by Craig on Dec 6, 2011 23:46:07 GMT -5
Hi Buckshot, When do you want me too meet you at the farm  ? lol Rick said that he was also free and could come along with me ;D I hope all has been well. Take Care, Craig |
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Post by Ryan on Dec 7, 2011 1:04:49 GMT -5
When I think "pockets", I think calcite and flourite in dolomitic limestone vugs, herkimer diamonds in dolostone vugs, or amethyst in clay pockets among saprolitic granite. However, when it comes to pematite, it is my understanding that physical "vugs and pockets" are rare due to high heat and pressure at the time of emplacement and mostly limited to rare gas bubbles.
That said, I would shift my focus if I were you. I know there are pockets in the hiddenite area deposits where Jamie Hill has found some real stunning material but most emeralds ive found (which are few) were not in pockets but on a biotite crust on the pegmatites outer region at the contact zone with biotite or chlorite shist. (Yes, as in the crabtree). And about 100% of the beryl (and most schorl and elbaite) ive seen has been not in pockets, but in the pegmatites core margin in highly mineralized portions of the feldspar/quartz matrix. Have you been able to locate any indicative minerals like muscovite mica, biotite or schorl within the feldspar/quartz? At some beryl bearing pegs Ive dug on in the SE, these minerals were always present to some degree. If I were you, Id be busting blocks of the stuff looking at the contacts between the feldspar and quartz, as well as surveying the outer contact of the peg and the country rock or shist or whatever is above/below/beside the outcrop. You may find beryl, apatite, columbite, large schorl and muscovite books, garnets or if your extrememly lucky, maybe even aqua or emerald!! Ill be glad to help you excavate and prospect the peg any time. ;-) good luck and please keep me posted!!! Post pics!!!
P.S. i WISH there was even a remote shot in hell there would be a pegmatite on my property. But nooooo, im propped up on 300 yards of barren boring sandstone and shale. Im very envious of your find! Please keep me updated so I may live vicariously through you.
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Post by gsellis on Dec 7, 2011 8:34:27 GMT -5
Wow Buckshot. I am just waiting for you to tell us you found a Kimberlite pipe on your property too  |
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Post by buckshot on Dec 7, 2011 10:02:03 GMT -5
Ryan: Thanks, I've not dug any yet, but on the surface really mineralized is mica, quartz, feldspar and some real soft black which could be schrol. Nothing really to bust at the surface except digging in the vein which is soft except for the quartz & feldspar. Will post any pictures if I find anything if I remember the procedure, not too good at that. Ryan, a friend and I went to the Crabtree this past month and the material on my farm doesn't look like the material at the Crabtree unless it is covered in the vein. I've had someone who knows more about geology than I say this is a typical pegmatite vein.
George: Who knows about the kimberlite pipe, there have been diamonds found in the stream that flows through the property, largest ever found in NC was found in this community, 4 1/3 carats. I know some on this forum may think I'm just talking, but I'm only telling what I see.
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Post by 41dave on Dec 7, 2011 11:09:47 GMT -5
Hmm...although not impossible, I would say finding an emerald bearing pegmatite on your property when you've already found corundum would be quite rare. Here's why.
I say its not impossible b/c there is documented a pocket of corundum coming from either the Rist Mine or Adams Farm in Hiddenite back in the 70s. So there you have it, emerald and corundum from the same property.
The interesting part, in my experience, that when corundum forms in pegmatite it is usually white,gray or blue in color. I believe this is the case with the Rist Mine material. Corundum from pegmatite does occur in NC, Old Pressley/Woods Creek, associated with kyanite from various places in the black mountains are the two I can think of, and both of these are strictly whites,blues, and grays, you'll never find pinks or red hues associated here. I don't know exactly why, but it is definitely related to the trace minerals associated with pegmatite(or lack thereof). What really throws me for a loop in all of this is that chromium is the trace element that makes corundum red, but it is also why emeralds are green. Time to hit the books again, ruby associated with emerald, why can't it happen?
Back to your property, you've proven there is corundum there, but it is all pink,purple,red hues, very indicative of an amphibole and/or dunite intrusion in which the corundum forms in.
Back to your basic question, is it worth digging the pegmatite you've located. Hard to say, but you'll only know if you dig. Chances are it is just a simple pegmatite, with feldspar,quartz, mica, and perhaps garnet. The soft black you're seeing could be schorl, is it more of a powdery coating? Could be manganese. Being that it is "very weathered" you obviously have mineralization that is speeding up the decomposition of the pegmatite.
As Ryan said, it's worth it alone to have the possibility just to explore all of it in your backyard.
Good Luck,
-Dave
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Post by 41dave on Dec 7, 2011 11:30:29 GMT -5
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Post by buckshot on Dec 7, 2011 13:37:15 GMT -5
Dave, thanks, there is according to the geological maps a ultramafic body in the immediate area. I'm certainly no geologist but I think that explains some of the many different things I come upon from time to time. BTW the pegmatite vein is probably 1/8th to 1/4 mile from where I have found the rubies and as you stated all have been towards the red, pink, purple color, I had my sister a pair of earrings made last Christmas which were between a brown & burgundy which I would think would be sapphire, haven't found any corundum in lighter shades you mentioned. Down
below the pegmatite vein there is a vein that crosses the small stream that looks like real fine mica, possibly vermiculite and also the only quartz cluster that I've found on the farm. It would fit in the palm of your hand easily and has distinct small points with one larger in the middle. Deer gun season ends this Sat. and I may take a closer look at the pegmatite after that. A group of hunters have the adjoining land leased so I'm cautious this time of the year.
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Post by stevebarr on Dec 7, 2011 13:48:02 GMT -5
Aw c'mon, Buckshot. Where's your sense of adventure? You shouldn't let a little thing like flying bullets stop you. And, if the hunters do manage to wing you....I know a whole bunch of people who would be glad to come help you dig for the stuff on your farm.
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Post by romare on Dec 7, 2011 15:40:32 GMT -5
Well, in Hiddenite the emeralds are in pockets, but not in pegmatites. The veins that (sometimes) carry emerald are alpine type fissures containing quartz, mica, rutile, sometimes schorl, occasionally other minerals in smaller quantities. The veins that are in the deeper unweathered rock also carry pyrite, siderite, dolomite, calcite in large quantities.
The peg veins are the ones that may contain aquamarine, i.e. iron-but-no-chromium-chromophore beryl. Mica and schorl present but in a feldspar surround rather than the so-called diorite surrounding the alpine fissure type veins.
Corundum has been found in small quantities at the Adams property and the Rist-Ellis complex as well. I have a small tabular xl from the Adams from back in the seventies. Dave is correct in my experience in that all the corundum is white to blue, with some few gemmy cornflower blue ones coming from the Rist vicinity reportedly also in the seventies.
Buckshot, it is probably a simple peg but I would certainly chase it down the contact zone and see!
Mark
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Post by 41dave on Dec 7, 2011 16:09:55 GMT -5
...damn Pre-Cambrian faults!
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Post by Ryan on Dec 8, 2011 1:31:40 GMT -5
Well, on the odd chance that it is a more complex peg, or even just because you have found corundum and crystal quartz so far, Id dig the peg based on your high level of luck! Sounds like you are describing a well decomposed pegmatite which may mean any cool accessory minerals may have since also decomposed. But thats yet to be seen. You mentioned a mafic formation nearby and Ive read that pegs intruding a mafic body can have nice almandine or spessartine garnet occuring in them. I have also read that pegmatite in the SE rarely if ever opens into pockets, but locked within the rock, there could be nothing but feldspar and quartz, or there could be beryls, tourms, who knows?! Let us know what you find.
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Post by buckshot on Dec 8, 2011 2:06:08 GMT -5
I purchased one of the books by pratt & lewis which supposedly is the bible on corundum in nc, I think it had been out of print for years and someone recently reprinted it and I had my son purchase it off amazon for less than $40, had heard the original if it could be found could cost up to $200 it is like 400 pages. I was amazed at the different minerals in the book that had been associated with corundum finds, so based on that I wouldn't rule anything out. I assume when we're talking contact zone we are talking along the edge of the vein and also not too far from this pegmatite is a large rock outcrop the part exposed might be half the size of a small pickup truck bed and it is covered with small reddish garnets and just above the rock I dug with post hole diggers down maybe 18" and it was mostly just yellow mica. I think I need to read a little more on the pegmatite veins and the difference between a simple & complex one. Sounds like maybe a complex one would be most apt to have pockets with gems, is this correct ? Some of this geology is way over my head, but I'm having fun looking and chasing, sure beats all the hard work I did here as a boy growing up on the farm. Sometimes I feel guilty being blessed with all of this to play with when you guys know so much more than I do.
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gonzo
Senior Member
Posts: 60
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Post by gonzo on Dec 8, 2011 12:25:25 GMT -5
Living to the southwest of you there are several pegmatites I have found around me. Most are not what I call complex pegmatities, pegmatites having other minerals besides quartz, feldspar and mica. The two complex pegmatites I have found both have schorl, beryl and garnet. One has apatite also while the other has what looks like columbite. The beryl is not very common but can be facet grade in our area and has a color similar to peridot. A guy opened a mine down in Thermal City as an emerald mine but from what I saw the beryl was not emerald but this peridot colored type. If you don't see schorl for sure I would think it is a barren pegmatite and continue with the corundum hunt. Keep huntin though because there is much to find in your area. There is an amethyst location off of US-64 between Morganton and Rutherfordton and in Sugar Hill. Several beryl producing pegmatites just southwest of Morganton and up on Walker Knob. When they were replacing the bridge on Vein Mtn. Road they cut into some pyrite veins when I stopped to investigate. Never know what you find ;D.
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Post by Ryan on Dec 9, 2011 2:38:53 GMT -5
Yeah, complex vs simple just means more or less mineral species respectively. Contact zone is just that, a fancy way to say where two different types of rock are touching. Could be the outer rim of the peg butting up against the country rock or greenshist, or where quartz and feldspar meet up inside the peg in big specimins or little baseball chunks, thats all. For instance, Any solid chunks of feldspar and quartz mix that you find, you may want to crack open and inspect. Beryl forms on the quartz/feldspar contact zone commonly. In your neighborhood (WNC), beryl comes in just about any color. Blue, bluegreen, green, yellow, mustardy brown yellow, white and even pink! No red though, gotta go to Utah for that. And dang is that stuff gorgeous. I digress...back to your vein, Who knows what you might find, tourmaline maybe, garnets maybe. Wanna sell or lease some of your farm? Lol, sounds awesome!!!
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Post by Barrett on Dec 9, 2011 13:50:55 GMT -5
See if Scott Laborde can swing by..he knows and thing or two about pegs.  |
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Post by 41dave on Dec 9, 2011 13:54:10 GMT -5
That guy?!?! no way! he only knows quartz fissures. Hi Scott |
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Post by pegmatite on Dec 9, 2011 17:29:56 GMT -5
Don't write off a simple pegmatite as a waste of time as they can still produce some very impressive mineral specimens and sometimes gems. Many great beryl/aqua pegs are pretty simple from the standpoint of mineralogy. I know of some peg veins less than two feet wide that are loaded with beryl. Complex pegs are just that, very complicated from a mineral standpoint and zoning standpoint, generally the result of the introduction of lithium or phosphates. Complex pegs will have lots of feldspar, but what you want to find is albite or the variety cleavelandite. This type of feldspar is very platy or glassy and often has lots of small to tiny pockets. Nice things (crystals) can be found in these small pockets! Big pockets are very rare in pegs, especially in the southeast. If you find tiny or small pockets you may want someone to check them out for you. Many pretty rare minerals can be found in these small pockets and they can be easily overlooked.
Check out Mindat.org for any known mineral areas nearby. That site is far from perfect, but it may suggest what is possible nearby. Regardless of all that I'd encourage you to do some digging. Since it's apparently fairly rotten at the surface I'd suggest screening any clay or dirt. Never know what you might find. I've seen sweet beryl/aqua crystals found screening the soil near weathered peg veins. I'd also suggest checking out stuff with a black light. Some stuff, like apatite, autunite, and common opal may show up in shortwave uv light and give you a better feel for what's possible. As already mentioned also pay particular attention near the contacts with the surrounding country rock. These peg edges are often especially productive for beryl. Same thing for large chunks of quartz. The gemmiest beryls are often found in quartz. Good luck and enjoy the search.
Steve
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Post by arappaho on Dec 9, 2011 22:59:20 GMT -5
Yep, that's my boy! Always sleeping on the job! Lots of good info for you here, buckshot. Sounds like there's only one way for you to find out for sure....... 99% digging, 1% talk. Good Luck, Hope you find somethings nice, Joe |
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Post by buckshot on Dec 10, 2011 13:21:27 GMT -5
Thanks one & all, that's why I post on this forum, lots of knowledge and nice people willing to share it, have learned a lot from you about pegmatites as well as other things in the past. I guess Arappaho put it well for me, it now needs to be "99% digging and 1% talk". Will let you know what happens.
Buckshot
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Post by buckshot on Dec 12, 2011 19:04:27 GMT -5
Went to pegmatite vein to start digging since deer season ended sat. Have to rappel down into gulch and climb up half the other side to get to it. The surrounding material is really cinammon or pumpkin color with black specks in it then from the outside of vein towards the center there is a small black seam maybe 1/2 " then a small white seam and a small golden looking seam which appears to either be mica or pyrite all about 1/2" wide then white material moving towards the middle with larger pieces or quartz, feldspar and some pretty yellow small sheets of mica mixed in. The vein sort of lies in about a 45 degree angle and I don't know how deep just started working it. Haven't found any gems or pockets haven't cleaned up the material yet but there looked to be a couple small pointed quartz crystals but didn't look clear, most interesting thing I saw about a foot or so in the vein there behind the layers of rock was a small nest of what looked like grasshoppers or crickets, mostly dark brown with a light tan streak on their back must have been 30 or so of them. The rocks are pretty well layered and not that hard to remove except the harder larger ones in the middle. Worked slow so as to not damage anything if I did come upon anything. My farm is pretty good size and you might know this vein is right next to the property line maybe 30-40 ft and it goes toward the line. However I'm friends with neighbor, let him take his grandson to my creek to swim so I don't think it will be a problem even if it does extend to his property. The digging is not that bad other than trying to keep my balance of the side of the ravine, problem comes trying to bring the material out when I get through. Took some of material by son's house and he took picture from his smartphone or blackberry whichever it is and got it to my computer, I will try later to get a picture of the vein but he probably can't be without his phone that long so I'll try to figure that out later. Should have two pictures attached, the coin is a quarter, there is a nice piece of mica attached to the large rock to the right of coin don't know if it will show up of not. Attachments:
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Post by buckshot on Dec 12, 2011 19:13:24 GMT -5
2nd picture of vein materials the mica is to the right of coin. Attachments:
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Post by buckshot on Dec 14, 2011 17:49:46 GMT -5
Played like a ground hog again today for a couple of hours, wish I could do a good job with a camera or even a video so you could see what I've got here. Didn't find any gemmy stuff but it was fun and educational seeing how the minerals will line up along the edges and then how they will interact with each other. The large vein is almost vertical in the bank and there are small veins running horizonitally. Along the vertical vein on the left side the minerals form small distinct lines. There are also some veins running horizonally with some of the prettiest white mineral which I assume is weathered or mineralized feldspar and little sheets of mica. If gellis is back up in my neighborhood will be glad to show him the vein in return for a hour of so of digging with his ho mi tool. PM me george if you're coming this way.
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Post by Craig on Dec 14, 2011 18:03:02 GMT -5
Nice Work Buckshot!!!!
Keep the pictures coming.
Craig
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Post by Barrett on Dec 14, 2011 20:17:25 GMT -5
Thanks for posting the pics, Buckshot! I was all up in a peg last Saturday actually. Let me see if I have some video. It was a classic zoned with border, wall, core margin, and core. The amethyst were appearing on the border zone and we were getting very large feldspar crystals that held together some what near the core margin and some rather large books of mica. Here is a little snippet of video I took...you can see my hand at a couple points on the mica in parts of the pegmatite
Amethystguy
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Post by buckshot on Dec 16, 2011 8:45:46 GMT -5
Two questions I should have asked earlier, should I continue digging along the main vein that goes vertical or follow some of the smaller veins that run horizionitally ? also what causes the black on the feldspar & quartz is that mineral or from heat in the past ? Will try to attach some pictures of the vein. Attachments:
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Post by buckshot on Dec 16, 2011 8:49:59 GMT -5
Sorry can only post 1 picture at a time for some reason Attachments:
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Post by buckshot on Dec 16, 2011 8:51:03 GMT -5
pegmatite vein Attachments:
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Post by buckshot on Dec 16, 2011 8:52:44 GMT -5
Pegmatite vein pic #4 Attachments:
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Post by Barrett on Dec 16, 2011 10:56:12 GMT -5
Yes, that is very interesting looking. The black is more than likely manganese oxide or could be schorl. Make sure and check those areas if possible. That means high mineralization areas when you see that black. Look for any buldges, dips, or points where the pegmatite veins cross each other. Those are typically the areas of interest. Those are great photos!!! That 1st and 3rd photo are great cross sections of it!!
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? lol 
