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Hard Rock Mining Questions - Non Gold Related


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This isn't about gold and I know this is a gold oriented forum but there are a few geologists and miners with a lot of experience in many things so maybe someone can help...

My question is, how exactly do you go about mining and seperating a material like vein jade without destroying it? Seems like with blasting you risk blasting the vein apart too. Even if I did blast and broke the diabase into manageable cobble sizes that I could remove and process, how would I remove the actual vein itself without destroying the jade?

A little backstory, one of the minerals I'm prospecting for is jade and I've found some veins (nothing economic or gem quality yet) finally so I think I'm on track to finding something better and potentially worth mining. But it got me thinking - with ore mining you can just blast it apart since it's being crushed anyways. But with something like jade where the vein is in place in rock and you want to keep the gem material as intact as possible, what would be the best method for mining and extraction?

I have finally located a few veins, they are low quality material not worth mining and far too slim anyways. But even if these veins were good material I'm not sure I see a good way to remove it. I tried chiseling with very little luck. The veins are in either basalt or diabase and the rock is very hard and durable and the jade doesn't want to seperate easily.

Most jade mined or even just collected by hobbyists is float in alluvium it seems like, so I'm not finding much useful info online on how to approach this.

I'm attaching a photo of a small vein I found as an example, it's only 1/2" wide and low quality olive jade so not worth mining, but this is still the same rock and material I'd need to mine and work.

Also here is some gemmy good deep green material I just cut off a boulder I found. This is Wyoming nephrite, it was float but still had vein material attached so I think I'm getting close.

vein jade.jpg

jade1.jpg

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Also a second question: when you are diamond core drilling, how do you remove the core if you don't drill all the way through the rock? Since it's still attached at the bottom.

Someone told me to put a wedge in and break it off but it seems like if I drilled 6 inches in the wedge would just break the core off halfway at 3" or something...? Especially since I want to drill as small of a hole as possible (like 1/2" if it'll work) and can't get much of a wedge in there. Do you just drill a lot deeper than you want to sample to avoid this, or?

I have to pack the water with me so I really need to minimize the core size and amount of drilling I do, that's why I'm wondering.

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Ok haha a 3rd question too, but it's really the same just different area and rocks:

With crystals in matrix, is there any way to remove them? Or do you just need to blast and go after the vugs?

Here are some beryls (I think?) in situ I found in a pegmatite vein but I couldn't hammer them out to bring back to test.

beryls.jpg

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You have chosen literally the toughest material on earth to mine in situ. Jade isn't susceptible to feather/pin/wedge work although the surrounding albite/country rock may be friable enough to start by traditional quarry methods. Blasting won't help you at all but the problem is more about the inability to shock break good jade than it is about fracturing the stone. Try breaking your piece of float with a 16 pound mallet and a backing wedge and you will see what I mean. You and your hammer will break before the jade does.

Quality in situ jade deposits are rarer than hens teeth. The one I am familiar with is the Bagby, California occurrence. You will find that mining block jade requires incredible patience and more belief in the ultimate quality of the, as yet unseen, material than a Forest Fenn treasure hunter.

The brief answer is diamond continuous circular wet saws for the small stuff and starting a cut and diamond wire saws for block sawing. In the old days we used mud saws and the type of patience that's happy to see a little progress on a monthly basis. Jade is really tough material, as you are discovering.

In Bagby the answer was to pull the biggest block you could and then spend the next year slicing the block with custom large chain driven traveling circular diamond saws. Making a large saw blade isn't easy but with practice and patience it is possible to make blades exceeding 40 inches. I'm sure modern blades will be more effective but large size blades are still a custom job and probably still more cost effective when done in house.

If you find quantities of semiprecious quality jade the issue of overwhelming the market (cutting your own throat) raises it's ugly head. Good jade is more marketable if you limit the amounts sent to market. The jewelry industry is fickle and too much of one type of material at once will move the market away from your product. Stockpiling and limiting the number of buyers is the only long term solution. Gem quality jade is a different story altogether but the odds of finding gem quality nephrite in situ is incredibly slim. As far as I know the Bagby occurrence is the only gem quality jade in place and the gem quality material was only several ounces total over many years and many tons of salable mined material.

Jade being a carving/jewelry material you might find working the float to be more profitable than mining the seam. From what I can tell from the picture your jade seems to be somewhat blue and semi opaque? That's generally carving material. If I'm right about the color you may already be pushing into a crowded market with the blue Colombian, Chinese and Motagua Valley, Guatemala Jadeite. Pictures can be deceiving but you might do well to show the material to a knowledgeable jeweler who knows the market. I believe you might find one of those on this forum. :wink:

The beryls are obviously weathered and eroded. If the crystals appear to be salable as gems or you think you might find good specimen vugs in the country rock start by sledging some barren material to see if it can be broken easily. If so work your way closer to the exposed crystals and see if they don't pop free on their own. If not you will need to use smaller hammers, chisels and picks to break the material away from them. The portable diamond saw is the next option but the rock will inform you which is more destructive to value. Final cleanup is done on the bench. A foredom and impact hand piece with bits can be very useful but your most valuable tool in recovering gems or specimens is experience and patience.

Congratulations on your discoveries. Good Luck!

Barry

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It's just green, the camera probably added blues in to compensate for my black jeans or something, dunno.

So basically what you are suggesting (so I can get it clear in my head) is to quarry the rock in place with diamond wire saws, remove it in blocks, then make 2 slices into the block with the diamond circular saw to remove the jade vein out? Essentially cutting the top and bottom buns off the hamburger and taking the patty so to speak? You don't happen to have a huge old diamond saw from those days like 40" you'd want to sell cheaply by any chance? :biggrin:

Is the feather/pin/wedge method that thing where you drill holes across a boulder in a line and then drive wedges into each hole, then just tap tap tap on each wedge one at a time on down the line back and forth for like a day until it breaks in half? Always wanted to try that, maybe record a video of it in high speed for fun. Definitely too slow for what I have planned though.

What about core drilling? All the float material has weathering rinds so they look like common rocks (you can see the reddish brown rind about 1/8" thick on my sample perimeter, it's almost 1/2" thick by my leg but hard to delineate in the pic). Even once you learn to recognize the rinds still like 95% of the float I find is just junk and taking it all home and paying to use someone else's saw is getting too expensive. And the hammer doesn't always break it (sometimes it breaks my hammer haha as you noted). For big boulders I need to core them before I try to move something big. Did you guys core your boulders or did they lack weathering rinds in California? Is there a good way to do it with no water (it's technically a desert here)? Do you just have to drill a lot deeper than you want so you have extra core and break the core out wherever it breaks out with a wedge? Does the wedge method work with a real small core like 1/2" even? Just trying to figure this out because a core drill is expensive (to me) so I can't afford to make a mistake here, but I think I almost need one to be more effective prospecting.

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Green could be good. Pictures don't tell much about whether the material has appeal when cut. That in the end is really all that matters. Jade isn't an element like gold that has a set definable market and value. Unlike gold you may have to create and control your own market. If the material is relatively clear, has no dark inclusions or included veins, cuts and polishes well without orange peel, has character and an appealing color you have a winner but still need to package and market.

With the Bagby deposit the owners stockpiled the vast majority that was mined. To this day I see jade being marketed as Asian or Russian origin that is almost certainly being sold from that stockpile. I don't think any of the Bagby material was ever marketed in the rough in the United States. Beautiful material for the most part but the best profit was made by controlling the supply.

You won't have much luck with pin and feather when working with jade. Did I mention it's the toughest natural substance known to man? For that reason you will need to use abrasives to cut it whether it's diamond saws or mud and an iron blade. Pin/feather/wedge does work on most rock and isn't much slower than dexpan when you are experienced. Different story when it comes to jade.

We hauled the larger boulder float out with winches, sleds and bars. Lots of manual labor. If the boulder was too big it got left in place. For us the objective was to get workable material with the least effort. Moving big boulders means cutting big boulders so ultimate size was dictated by weight and the size saw we were willing to run. I did most of my boulder cutting with a mud saw and a 1 hp gas drive motor. A single cut could take a month. I can still hear the constant putting of that little Briggs and Stratton in my memories. It might still be running today.

The float was chosen by the quality of the "ring" that was heard when struck with a rock hammer. Identifying the float by sight wasn't always easy because there was a lot of albite and serpentine in the area. It's just a matter of hard earned experience. Not all float or in situ jade is of good quality. You put in the work and you take your chances. Jade deposits need to be judged by the overall profitability. Just like gold deposits not all days are profitable but if you don't put in the effort no days are profitable. I'm sure with time you will come to understand the float in your deposit too.

I don't have much experience with core drilling in the field. Drilling a hole all the way through a jade block will give you the start of your back cut for a wire saw once you have cleared the sides. The 40 inch blades were used in the off site warehouse with an overhead chain drive and X/Y table to position the jade block. Wire saws and smaller continuous circular blades were used in the mine.

The best profit I had with jade float was gathering smaller pieces, slicing an edge to judge quality and high grading the resulting material to find marketable pieces. That's a lot of work but I combined that with gold mining and semi precious stone collecting to feed my jewelry business and made a good living. I ended up with piles of lesser material behind the barn but the neighborhood kids loved digging through it for treasures and traders and other jewelers would pay by the pound for what they could find.

It was fairly simple to stop by my collecting area when I was out dredging or looking for specimens and cutting material. Loading up a two hundred pounds could keep me busy for a month. Occasionally I would spot a promising larger boulder and mark it for a later expedition with some labor help and winches, sleds and a home rigged crane. Often those larger pieces of float were a waste of time but once I found a really nice piece and made some good money from the slabs and cabs.

That's my experience. More modern and reliable tools are available today. You might want to contact the operators of the Polar Jade mine in B.C. They have quite a bit of experience with mining and cutting nephrite jade.

Figure_2_180430_636x358_1356007013320.jp

 

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Yeah I read all through their website before I went out prospecting for jade, that's where I got the idea for core drilling from, it seems to be their chosen method for determining quality in the field now.

My jade is not as vibrant and green as that big boulder, but it's close to some of the darker green stuff they have listed on their carving page. I have found some gemmy float like that though.

Anyways, thanks for the advice. I have another question for you too but it's not about mining methods per say:

If there existed a situation where a person can't get access across private land to federal land, (assume it's completely impossible to obtain permission for whatever reason), but that private land was surface rights only and the mineral rights under it were open for federal staking, what surface access rights do you suppose a person would gain by claiming those mineral rights under the private surface? The BLM gives varying opinions and I'm reading varying opinions online too. Could a person gain access to cross that private surface to the federal land locked up behind it? Or would their access rights be limited to actions incident only to their claims under that private surface?

One step further (because I think I may predict one potential response?), let's assume a valid claim could be filed on those minerals without even stepping onto the private surface. Say for instance you could prove a historic vein extended from federal land and under that private surface land in question. Or assume you have old mineral surveys which delineate the strike and dip of the vein too. Could you at least walk onto the private surface to pound the stakes in the ground to make sure the claim was complete? Or would that be a trespass still?

Which leads to another question: If a claimant does have access to private surface then how much surface disturbance can they do? And if they can make surface disturbance for mining activities, then do those activities need a NOI of POO since the surface is private? This was another point of contention I can't find any answer on.

In other words, can you mine federal minerals without a NOI if the surface is private? Assume the land is vacant, zoned mining or ag, and has no other plans, covenants, or other instruments preventing mining.

I realize of course the best way is just to negotiate leases for access and this is why landmen do this for oilfield access and whatnot. But in some cases it's impossible, I've run into it for varying reasons in a number of different states now.

Just curious, I know you know a lot about these things and in this particular case I'm coming up with so many conflicting opinions and writing that I honestly don't know what to think. Maybe it just comes down to a state level issue? In fact standing in the BLM today I had the surface mgt guy telling me a-ok and then a rancher standing next to him getting a permit saying he was totally wrong.

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