Mine specimen collecting techniques?

I'm fairly new to rockhounding and mineral collecting and could use some suggestions for specimen collection techniques. Specifically, I'm looking for ideas on how to remove samples in these three situations:

• Removing crystal formations from small vugs or cavities in the walls of mine shafts
• Removing tough-to-collect samples from the face of mine shaft walls (for instance, Molybdenum which flakes apart when chisels are used close to it)
• Removing whole or nearly whole mineral-filled vugs from huge boulders

I'd like to know what tools, including size if important, others use in these and similar situations. The host rock from which the specimens are being collected is hard lime stone or ryolite depending on the area I'm working.

Ken

That's a tall order you have there. Firstly and most importantly, have you ever collected in a mine shaft? I have been doing such collecting for several years and the first and most important consideration is "SAFETY" and I can't stress that enough. Since you say that you are new to this, I would suggest going in with an experienced person.

You will probably get many different answers to you questions since everyone has different methods that they employ. Try and get as much matrix as you can around the specimens if possible. Thatway the small vugs may stay intact for later removal. Use as heavy a mallet as you can handle. It is better to remove what you want with two or three whacks then many smaller whacks. That avoids setting up a repeated shock-wave which often destroys the crystal.

Al

Ken,

Our mine is open pit so i do not have any knowledge of working underground. The best tool for removing small pockets is a gas powered cut off saw. 14" saw is the best balance of weight and power, you can get bigger but you do not get much more cutting depth for the weight gain as it can get tiresome holding a saw for long periods. The gas fumes could create problems for you underground for prolonged periods of time. We use the saws at a quarry to collect fragile fluorites that normally shatter using normal collecting methods. I have seen people using cheap of brand saws and they do not stand up to the abuse so i would stick with a name brand like Stihl or Husqvarna as they are easy to get parts and service for. We also use a gas powered 16" diamond blade chainsaw, but it and the chain are expensive. The most bang for your buck is the cutoff saw as they can be used dry or wet. If you have fragile specimens the make soft blow chisels which absorb the impact and are great for the fragile specimens. You can see pics of us using them at our website www.toveco.com

Hope this helps

Lee Champigny

Hi Ken,

Just some random thoughts regarding the scenarios you present. As regards number three, a lot has to do with the type of rock you are dealing with. Are you looking to break down Basalt, Limestone, Diabase? Much of this work can be accomplished with brute strength, sledge hammer and chisel. But, describing how to do it, generally is difficult. You need to see how the rock fractures and of course, attempt to minimize the shock to the crystals inside the vug. I learn by example and so watching my more experienced friends hack up things, has been a great learning experience. There was a great piece of advice offered here the other day about duct taping an open vug to prevent crystals popping out.

As far as collecting in a mine shaft or adit, Allen is right on target with his advice. The first reaction from any collector reading the question posed is not necessarily alarm but concern. I recall reading about two experienced collectors who went inside an old copper mine in Arizona, collected without issue for some time and suddenly, without warning, a huge rock dropped from above, severely injuring one collector's leg. I'm not going to belabor the point taken about safety so I'll just ask you to give thought about providing more information about what you wish to collect. For instance, are you looking to open up pockets in a mine? Are you looking to "harvest" exposed crystals, let's say Galena cubes from a shaft wall? Again, specifics might yield you a more substantive reply.

I don't work with saws although I'm giving serious consideration to the possibility. Much of my work is done with sledge-4 pound crack hammer, cold chisel and a rock hammer. Trial and error is not necessarily a bad thing with your Molybedenum crystals or a vug filled boulder, in the absence of any substantive sculpting advice, but trial and error in a mine shaft is a risky proposition. Get in, get done and get out is the name of the game in that scenario. There must be someone experienced in such specimen recovery in your area who would be glad to assist.

Molybdenum will not flake. Molybdenite will!

David wrote: "suddenly, without warning, a huge rock dropped from above, severely injuring one collector's leg". Dare I say, "Snap"? I still have a metal nail in my left tibia after the same happened to me. Being able to see a major bone sticking out of a ripped open leg is not fun. Perhaps something Ken should consider having is INSURANCE! Thankfully I did, and the payouts that followed were most welcome at a difficult time. Would not say it was worth it though. 6 weeks in hospital and over 6 months off work, and nearly a year out from collecting. Back at it again though, and using tools that Ken would find useful. These include a petrol (that's "gas" for those on the other side of the pond) powered saw with a diamond edged blade. I agree with Lee that these are brilliant. They are available from hire shops, and I would suggest hiring one first to gain familiarity before spending big sums on a new one. Water cooling helps keep the dust down (good for the health) although I have run them dry too. Here are some examples of things I have collected using such a saw:

[www.mindat.org] [www.mindat.org] [www.mindat.org]

Saws are also great for general trimming.

Another useful tool, and one which has no issues with fumes (which is obviously a limitation on petrol powered equipment if you are going underground), is a cordless drill with SDS bits. With modern lithium batteries one can get quite a few drill holes out of them nowadays. These can be very useful for making grooves or holes for chisels to bite into, especially if working at an awkward angle and the chisel is glancing off. Friends of mine have used them to great effect in the tough silicified limestone of the Nenthead mines. You can get petrol powered ones too, which have much more power and last longer, but again are best used outside. The Chinese ones are cheapest but tend to fly apart at the chuck, and as they do a tiny ball bearing disappears into the dirt leaving you cursing and with a useless drill. Ryobi used to make a great machine but no longer, so far as I am aware. I have recently acquired a set of plugs & feathers (wedges & shims) which I hope to use in conjunction with a drill in granite next spring. I know where there are some nice miarolytic cavities ...