A question about black sand.

[captain Kidd]

Hello. I have posted a lot over at the metal detecting forum in the past but I have a question about black sand. I read an article about micro gold attached to black sand. My son wants to do his science project for school on this. We live in southern Colorado in a sandy desert area. We have collected a large jar of it with a magnet and my question is how do we separate the Gold if there is any? In that article they collected theirs on the beach with a sluice and sent it off to be processed. Is there a way to do it ourselves or can anyone recommend a place to send it. We are surrounded by Gold mines. Summitville is to our west. Bonanza is to our north. There are placer deposits and many mines to our east in the Sangre De Cristo range. Thanks for any help.

[captain Kidd]

I forgot I was going to add this story for your enjoyment. A man from here was working grading roads in the national forest. One day in the 1970's He was grading the road the the Summitville mine just west of us in the San Juan mountains and he saw a strange boulder on the side of the road. It turned out to be full of gold, over 300 ounces. He sold it to the Denver Museum of Natural History. His name was Elithorpe and I have seen it there in the mineral section of the museum. I bet he wishes he would have found it now with Gold at $1,400. an ounce.

[Frank1960]

I read an article on the black sand and the magnet also they used some kind mercury I think and I think they mentioned something about using soap. Ya might ty googling it. Good Luck!

[Bumpstick]

I saw where some one would soak it in lemon juice which is acidic to clean it then rinse.
Then roast it and maybe freeze it to fracture it.
Then pan it out or run it through a blue bowl.
Do a search on black sand clean up.
Collecting it with a magnet would be different than what would be in a sluice box.
I saw where some one dried, then roasted it and added mercury to come up with an amalgam.
That was retorted to gas off the mercury for recovery and leaving the gold behind.
Caution !! You must know what you are doing with this proses and I do not recomend it.
It can be very hazardous to your health. Just handling mercury is Toxic. XXX
Not a good science project. Except in description and some pictures of the proses.

[strickman]

roasting b.s. in a iron skillet ,then pour in cool water-will fracture the black sand . releasing more gold . but be careful ,google it for specifics -it does work .

[kilnmaint]

Cast iron pot full of black sand in a roaring fire. It takes an hour or so . There is an explosion when you dump the hot sand in the cold water , so watch out!! It will crack the sand and release gold if there is any there to start!

[Gravel Hog]

Is it worth the trouble? Probably not unless you are talking about a dump truck full.
Better to just get the visible gold out and put forth the time towards finding more.
But I guess it does make for a fun science project in the winter if your desperate for it.

[Astrobouncer]

I see black sands like this: Whenever I am sluicing, panning, etc, I get some small amount of gold and a large amount of black sands. I have already captured these heavies so the work has been done. By throwing them away, I am basically throwing away work. Might as well store them for later processing if you have the room, and accumulate enough of them. That small amount of gold in black sands adds up, especially over the long term if you get a lot of concentrates. Robert up at Lucky Strike (near vein mtn, NC) showed me a 1+ oz button he had smelted from microscopic gold in his black sands. Now if you only have a little bit of blacksands, and it is not from a gold bearing area; then its doubtful you will find much (if any) gold locked up in there.

I save the plastic containers from coffee and fill those up with my concentrates for later processing after I pan out the bigger gold. One day when I am bored or cannot prospect, I will roast those cons, then drop in ice water, then run through a miller table.

[M_M]

Is the rock black sand comes from a host rock for gold?

or

Are we breaking it down so the rock is smaller to wash away easier from the gold as the black sand grabbed it when the magnet pulled up the material?

[strickman]

there is different colors of gold in cons.some is even black. some gold is in the b.s. locked up. fracturing releases this gold . ever seen a piece of b.s. with specks of gold on it , it's there just look at it with a jewelers loop.

[captain Kidd]

Thanks for all of your advice. We are trying the cast iron skillet in the fireplace and water, very carefully. There should be some gold present. The black sand has been deposited from the San Juan mountains. Gold has been panned from the sand at Great Sand dunes National Park 25 miles East of us. IT caused a short lived gold rush with people filing claims on the dunes until they realized the work involved in getting the gold out. This was in the 1880's.

[highdesertranger]

whoa slow down, by firerplace do you mean indoors? i personally would never heat any rock/mineral or black sand indoors. to many things to go wrong. be safe please, outdoors and be upwind. yes i think you might find a Little gold if you are down stream from a gold bearing area. be safe and good luck. boy i love spell check. highdesertranger

[captain Kidd]

We heated it in an old stove outside. Used hardwood and an old cast iron skillet. The sand was incandescent orange when we took it out of the fire. We transferred it to a bucket of cold water in small amounts with a long handled fireplace ash shovel. we will try to separate the gold by panning. Will let you know if we get anything.

[captain Kidd]

Well here is an update. I couldn't wait till tomorrow. I was panning a little to remove the ash and charcoal pieces and saw a tiny, tiny flake of something in the bottom of the pan. Got it out on the tip of a razor blade and looked with a loupe and I'll be drawed on it sure looks like gold. Will do the rest tomorrow as it is dark here now.

[Golden member]

There are a few ways to extract gold from black sands, one of them is to pulverize the sands and run it all through an aqua regia solution which disolves the gold into the solution, from there you add another chemical to the solution to have the gold drop out. It is quite dangerous but apparently quite effective. You could also pulverize the black sands and run it all through a mercury bath as mentioned and then run that through a chamois and finally a retort. It too is dangerous. The heated black sands and cold water idea is the safest but still could be dangerous in an elementary school class room, also it would release the least amount of available gold from the sands. On a similar note most black sands from these gold creeks are also quite rich in the Platinum group elements like Platinum and Rodium and ummm, I can't remember the others but they are worth more than gold.

[3xflyfisher]

Hi Captain,

To expound on your story a little. Bob Ellithorpe was an employee of Asarco and as indicated was coming down off South Mountain after a thunderstorm driving a dozer. He caught a glint out of the corner of his eye and hopped off the tractor to go look. The glint he noticed was actually gold wetted by the recent thunderstorm on the face of a rock that would become known as the Summitville Boulder. If memory serves me, the boulder weighs in at about 100-150 lbs and contains 350 oz of gold, +/- 10%. He then turned it over to Asarco for a $10,000 finders fee; Asarco then donated the boulder to the Denver Natural History museum. I had met Bob back in 1980-1981 when Anaconda Copper Co was doing exploration work on the property. Anaconda eventually went out of business and sold the property to Galactic Resources who started a large heap leach operation to recover the gold. Galactic then had a large cyanide spill and associated environmental mess that closed the mining operations at Summitville.
Bob indicated that after unearthing the boulder, he and several other folks spent many weekends hiking up and down the flanks of South Mountain hoping to find the outcrop that the boulder came from. They were unsuccessful in their attempts to find the origin of the famous boulder.
Many thanks for the memory!
3xflyfisher