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Breaking rocks for gold?


Blarneystone

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Hi all,

My kids and I pick up quartz when we are traipsing around the woods and take them back for rock smashing. Some are found in the streams, some are found in dried up river beds.

I crush them up fine and sift them to about 30 mesh and then run them through a homemade gold concentrator. About the only thing I've found so far is what appears to be a tiny shred of what looks to be platinum or silver that sat at the bottom of the concentrator when all the sand was gone.

I was just wondering how much luck you may have had crushing quartz? Is it a mostly useless activity? If not, what do you look for before you crush?

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Hi all,

My kids and I pick up quartz when we are traipsing around the woods and take them back for rock smashing. Some are found in the streams, some are found in dried up river beds.

I crush them up fine and sift them to about 30 mesh and then run them through a homemade gold concentrator. About the only thing I've found so far is what appears to be a tiny shred of what looks to be platinum or silver that sat at the bottom of the concentrator when all the sand was gone.

I was just wondering how much luck you may have had crushing quartz? Is it a mostly useless activity? If not, what do you look for before you crush?

Howdy BS,

On any outing I examine more quartz that I can handle in the hope that gold will be visible. I've probably picked up tons and it ain't happened yet. The only samples that I bring home are the crusty, rusty kind because I was given a bucket of quartz from a working hard rock mine and the quartz was crusty and rusty and contained fine gold.

Two weeks ago I camped a Burro Creek. About 3 miles from camp in the middle of nowhere I came across what must be several thousand acres of scattered alluvial Quartz. I spent hours examining. No visible gold. Could spend a month of Sundays there and go blind with the effort.

Good Luck'

Bill C

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There is lots of quartz out there and just a little gold. I crush hematite/quartz all the time and get good gold. But in a vein the gold is generally NOT in quartz around here, but rather in hematite.

In a gold bearing area the vein structure and gangue material is always special. In some areas it is the red stained quartz and in others it is the rusty quartz. In others it is not in quartz at all but calcite. You need to research how the gold in your area came and look for those indicators.

My experience is that a detector will alert if the gold is big enough, but I have steady 6 opt ore that makes no sound at all. Specimens with free gold in a visible quantity rarely make a sound unless there are particles big enough. In some districts all ore is detectable and in others none is. Ore from one vein may sound off loudly and show a little gold while other ores will make no sound and have a high quantity. And sulphide ores can be fantastically rich and will NEVER sound a detector.

So the trick is to find out the individual characteristics of the ore in your spot. I have found that once I locate the gold bearing ore that it is easy to spot and you can get fantastic recovery from crushing quartz. Just not ALL quartz.

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So the trick is to find out the individual characteristics of the ore in your spot. I have found that once I locate the gold bearing ore that it is easy to spot and you can get fantastic recovery from crushing quartz. Just not ALL quartz.

Most of it is in white quartz in my area. I do pick up the shiney "rusty" ones, the ones that appear to contain metal and the white ones you can break with your hand.

Its funny how you can start with this shiny rock that looks like it's got alot of metal in it but it crushes down to dust :tisk-tisk:

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Most of it is in white quartz in my area. I do pick up the shiney "rusty" ones, the ones that appear to contain metal and the white ones you can break with your hand.

Its funny how you can start with this shiny rock that looks like it's got alot of metal in it but it crushes down to dust :tisk-tisk:

In my particular neck of the woods it is about 20% quartz and 80% hematite gossan that you look for. It is red like chile powder. In each area it is different and you should consult your geological and mining records to find what the goodies look like.

In my experience NO QUARTZ that has large crystals are any good, and no quartz that is solid is good. Only float with a bit of quartz and an abundance of hematite. But each district is different and even within districts the ore changes dramatically.

A good rule of thumb is "rusty rotten quartz". It is a wide generalization and there are three types of "rusty rotten quartz" in my area and only one type holds gold.

Any "metal" in the quartz would be a sulphide or a chloride and not a free native metal. I have never seen native metal in a free gold vein aside of the occasional silver wire. Methinks you are seeing mica or pyrite and identifying it is metal. When you see mica or pyrite around here you are in the wrong area and the quartz is as barren as Hillary. Again, different areas are different and the recorded knowledge is the only source for the info.

Look in the mining records and on the mine dumps. The gangue material will be readily seen and you wont have any trouble identifying it when you see it as float. And a good 30X loupe will tell you a lot more about the gold content of an ore than a detector will. That is just my two cents for what it is worth.

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Thanks Bedrock Bob that sounds like some of the info I was just asking for! speechless-smiley-016[1].gif *looks at rocks on google* man! the rocks come in so many variations !!! I guess this is not something I will learn a couple weeks but only after years mad0229[1].gif

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Each area is definitely unique. I see California quartz ore and it is just alien looking. It is in that deep intrusive geology. Here the native gold is within the first 12 feet or so and turns to sulphides within the next 100 feet. So all the ore is oxidized well. There is no use looking at rocks from depth where the crystal structure is large and the quartz is big and solid. But that does not play everywhere.

I figure the only way to narrow down what type of "quartz" the gold is running in is to learn it from an old timer, read it in a journal or publication, or find it the hard way.

That is why it is so dog gone important to know the history of the area you are in, and have a description of the ore and the extent of mineralization. Even with a good description of the ore I have to go to the various mine dumps and familiarize myself with the ore being taken out to locate any good float.

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Here is one from hematite that was formed near the surface, to contrast with yours formed down near the devils doorstep somewhere. The quartz was fine grained and scattered through hematite the color of a cake of ground red chile powder.

I call it the lobster. You are looking at his claws. He has a hematite shell and his tail sticks out the other end. And I found this one just like El Dorado suggested. With a Gold Bug II.

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Hi Bedrock, This is how they grow em here in CA, on rare occasion..

Don't see many like that, I have a spot where we have found just 2, but not clear like yours. The crystals are stained rust red...

These specimens are from the same spot, sorry for the quality just took it with my cell phone.

IMG_20101109_071104.jpg

Bob, I also a a gossan stalker as well, here in AZ areas like this give up some nice nuggets to my detector now and then.

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The Prospectors Club of Southern California has a claim named the "Red Chispa." One of the types of gold found on this claim is of the decomposing "gossan" type. Last week after one of my court related cases ended a little early I drove out to the Chispa [as we call it, for short] and scored one of those gossan nuggets with my GB2, weighing around .4g. I will make an attempt to utilize my almost non-existent photographic abilities to take a photo of it [currently soaking in CLR to remove as much of the red crust as possible -- when first recovered not one speck of visible gold was apparent, but after several days in the CLR a lot of it is starting to show]. The interesting thing about this particular 20 acre claim is that there are several totally different types of gold found on it. Some [many of the larger ones] are as smooth and nearly as rounded as a billiard ball. One type of crystalline nugget is a butter yellow, another more silvery color is less common. Then there are the many red stained gossan pieces. Lying smack atop major segments of the Garlock Fault with three separate drainages probably accounts for this rich mixture of gold types on such a small claim.

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Don't see many like that, I have a spot where we have found just 2, but not clear like yours. The crystals are stained rust red...

These specimens are from the same spot, sorry for the quality just took it with my cell

Newbie question: I have found quite a few that look similar - gold color on outside. But when I crush them, they turn to white powder. How can you tell? Do I definitely need a metal detector?

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Here goes, let's see if I can attach my photos. There are two views of the gossan nugget [front and rear] plus alongside another nugget I found within a few feet of the gossan nugget]. This latter nugget at first was coated in rust and weighed .4g, but after soaking in CLR for two weeks it cleaned up and dropped in weight to .3g.

post-1713-019967200 1289327004_thumb.jpg

post-1713-080386800 1289327064_thumb.jpg

post-1713-077083800 1289327110_thumb.jpg

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Here goes, let's see if I can attach my photos. There are two views of the gossan nugget [front and rear] plus alongside another nugget I found within a few feet of the gossan nugget]. This latter nugget at first was coated in rust and weighed .4g, but after soaking in CLR for two weeks it cleaned up and dropped in weight to .3g.

Micro,

I use HCL to clean the iron off. It has a great affinity for iron (hematite) and I can burn a whole lot of red glick off the gold in a big hurry with it. It is a lot cheaper than CLR too (which is just weak phosphoric in a gel base I think).

I set up a small alcohol stove (the kind made from an aluminum beer can)and use a pyrex beaker on top. The hematite boils off in seconds!

The hematite gossan is already weathered by definition. Many gossan nuggets will be found clean already. I generally find mine in situ and not as chispas or placer. Where gossan nuggets are found pockets usually abound. The hematite veins pinch and swell and are rarely ever continuous, so in an area with gossan gold it is a good bet for hard rock pockets to be found at grass roots depth.

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CLR is a concoction of several acids and other things but no phosphoric acid. Phosphoric acid does a very good job of turning red oxides of iron into a soluble oxide. I recently used some concentrated H3PO4 on an ore and the ore turned pure white in a few hours hours. Concentrated H3PO4 can be had at ACE hdw. for about $15 a gallon. No heat or fumes and does a job on rust. Also if you like Coke A Cola phosphoric acid used in the formula to add a little tangy taste.

Got rusty pipes? Drink a Coke!

Bill C

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CLR is a concoction of several acids and other things but no phosphoric acid. Phosphoric acid does a very good job of turning red oxides of iron into a soluble oxide. I recently used some concentrated H3PO4 on an ore and the ore turned pure white in a few hours hours. Concentrated H3PO4 can be had at ACE hdw. for about $15 a gallon. No heat or fumes and does a job on rust. Also if you like Coke A Cola phosphoric acid used in the formula to add a little tangy taste.

Got rusty pipes? Drink a Coke!

Bill C

I use phosphoric to etch steel for painting and to clean brass casings. What a stink. Whoda thunk they would flavor anything with that? Tangy is just how I would describe it. Tangy as a prospectors behind after 12 hours in the Arizona heat.

Now I know why I dont drink soda pop.

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Bedrock: I first soaked the gossan nugget in phosphoric with not too much of a result ["PH Down" available at pool supply places]. Then I put it into the CLR and scrubbed periodically with a soft toothbrush. That seemed to do the trick. Maybe the phosphoric "prepped" the gossan for the CLR bath?

BTW, you are right on about the pocket gold on that claim. One that I know of contained over a pound before it was cleaned out [not by me] and it was not very deep, as you mentioned. There are caliche "bowls" there that sometimes yield up several pickers -- some in the bowl and some in the caliche itself. The phosphoric cleans up the caliche pretty well. Thanks for sharing the info.

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