Reno Chris

I was talking to a friend (Wes D.) the other day and he was telling me a very well known specimen mineral dealer whom several of my friends have sold gold to no longer uses HF to clean or alter specimens because of the unnatural "frost" it gives to the quartz (HF eats up quartz, but not gold). The guy now uses only dremmel tools and removes the quartz by hand.

So if there is not really any crushing going on in the mixer, is it just to wet and mix the material prior to treatment? With the comparativly small amount of material you are crushing, perhaps a little assay lab type jaw crusher to reduce stuff to minus 3/4" - sometimes these can be had cheap used on ebay, craigs list or some such source - maybe even the ICMJ classifieds. Thats what I have......

Also the fourth version - the TDI they call a GMT SuperPulse. (although its generally not available here in the US).

The Keene thing is an impact mill - and actually they can be fairly high wear as the impacting quartz does wear pretty good on the impact plates. As long as you are not crushing large amounts of material the low cost counteracts the high wear cost, so they are good for semi-pro / amateur use. (way better than a dolly pot) As Mr. Gaber says, over crushing is to be avoided for lots of reasons, worst of which is loss of values. Its this fact that caused the death of the stamp mill a century ago. The only way to avod over-crushing is to have some screening step. In a ball mill you can have an integral self classifier that keeps in the coarse and lets the material that has reached the desired size move on to be processed - thats the standard commercial set up. I have seen some small 3 - 4 foot diameter ball mills that are small enough for a small mining operation. Mr. Houston - do you use iron balls in the concrete mixer?

Commercially, rock crushing is done in multiple steps. You should consider the same type of set up. My suggestion is that you consider a small jaw or cone crusher that will take 4 inch minus and take it down to 1/2 minus, then take the 1/2 minus and use your existing crusher to go down to minus 100. A big commercial mine would probably use a jaw to go from 24" minus to around 3 inches, a cone to go from 3 to about 1/2 and a ball mill to go from 1/2 to whatever the goal is - 100 mesh or whatever.

I'd say its galena - probably with high silver content to make it conductive. The light colored stuff is Anglesite, a product of weathering on Galena. See: Anglesite mineral info

Hi Condor: Part of this shows just how difficult identifying minerals really is - even with a really great photo and how much more difficult it can be just from a verbal description. People perceive things differently, and describe things differently too. The galena photo that chickenminer posted is something I would never describe as "jet black" - to me that's gray. The problem is that you know what you have in your head, but I am probably imagining something totally different. Here is a picture of what I think of as jet black and porous. This is a mineral that is found in the Red Cloud mine - but it looks lots different from the galena photo. Here is a web page that describes the geology and some of the minerals found in the Red Cloud mine - a silver lead mine with lots of other stuff and quite famous for its wulfenite specimens. http://www.mindat.org/loc-3348.html I am interested in talking about it - lets see about getting a good photo - at least that would help a lot.

No. I will be in Mesa for the GPAA show in January.

OK. No worries. I had a guy bring me a hot rock from down that way a few years back and it screamed even in discimiminate and showed metal on VLF coin machines - it was a chunk of cuprite a copper ore - a conductive mineral that is often dark colored.

There are no real magic things to do to make a dry washer recover like a wet system. Just the common sense stuff: Don't overload the riffles with too much material too fast and don't let the thing run while you are not putting any new material across the riffles. Always make sure your material is fully dry before you run it - etc.

An excellent book with lots of good info.

There was no warp in the space - time continuum yesterday, nor did I see a smoking crater to the east of me this morning, so it must have gone OK. On the other hand, all the damage could have occured on a different reality plane - you never know with that sort of thing. A few more days of this warmer weather and you'll be able to take them out in local parks and schools. After Christmas sometime?

Interesting that for a mid-frequecy, general purpose detector, the GB Pro is probably the weakest of your group at coin and jewelry shooting. Great for gold, only OK for hunting coins and the like. Some of the choices you turned out are more truly general purpose, but when a design engineer is trying to build a do-it-all machine, compromises are required.

Thanks for the kind words. I've been prospecting since the mid 1970s, and ended up getting a degree in Mine Engineering at the Mackey School of Mines - part of the University of Nevada. Yet even though I got my degree, I kept up panning, dredging and otherwise prospecting out in the field - because I enjoyed it. What you know makes all the difference when you get out in the field, and as I was looking at the books available, I saw that most were written in the 1970s and 80s and did not include a lot of info which I thought they should. So I spent 10 years working off and on to produce a book that had all the info I thought a book on prospecting and gold mining should offer, including all the new info on metal detecting, because the world of technology has changed since 1980. The book has been a big success, in the 4 years since it came out, I've sold more than 6000 copies. Its available at most prospecting stores and through Amazon.

How was the EMI with the infinium coils on the ATX?

Probably more an effort to stir up interest in watching the show than actually wanting people to apply. The effort made is real minimal. I've not seen them really add anyone new. Years ago, I heard and interview of Red Skelton (a comedian from the 40s-60s) where he said that when he'd come to a town to do a show, he'd call up all the bars and clubs in that town and have them page for Red Skelton. He swore it helped him sell tickets because people heard his name. There are many tricks to show business.