Looking For Some Wisdom

[Zincoln]

Good day.  As there are a number of very capable prospectors on the site, I'm hoping my pictures are detailed enough and that you may have some perspective/insight on what i think may be gold in an ore sample.

I found this metal detecting at a known gold site in NE Oregon.  While the specific site wasn't known for hard rock mining (rather placer), there was some hard rock mining a few miles away.  I was getting a good low conductive signal on my V3i, and out pops this fist sized rock from about a foot down.  I could see clear indications of specimens in the rock, but it had more of a silver hue (some of it appears black - like silver would oxidize) and occasionally had a brassy appearance to some of the material in question.  Quite heavy.

Testing done:

- confirmed non ferrous with a rare earth magnet

- extracted several 'nuggets' from the ore with an ore crusher.  I was able to take one and flatten it out nicely with about 3 whacks from a 3 pound sledge. Not brittle.  Quite a bit of very small quartz crystals in the matrix of the 'nugget' specimens.

- used acid tests.  The piece i flattened seems more of a silver tone, whereas others have a bit more of a brassy appearance.  18k acid did show the streak lighting up blueish, but the silver acid test showed no reaction.  Took 22k acid to begin to remove the scratch.

- ran the little nuggets past the V3i and the Deus - both hit in the low conductivity gold range (about the same as a 22k earing back).

'Nuggets' are all about .2g +/-.  I dropped them into muriatic acid to clean them up a bit.

I am not aware of any silver mining in this part of Oregon (but I'm not well versed), and i don't find ore examples of silver that have similar visual appearance.  The closest thing i can find for comparison is Calaverite, but also not aware that this has been found in Oregon.  This rock does seem a little out of place for the area, so it's possible it came in from elsewhere.

Anyone know if we have any gold/silver compounds in Oregon ore that might produce silver hued gold?  Other mineral?

Next time I sell some gold I'll have to take the little flattened sample and have it analyzed with a spectrum analysis machine.

 

First image (IMO) makes the samples appear a bit more gold than they do out of the sunlight.  Piece at 3 oclock is the piece that was flattened out. 

For comparison

 

Initial large sample.  Lots of this material throughout the sample.

Following pictures are close ups of 'nuggets'. 

Flattened out piece

Large ore sample with areas that have more of a 'gold hue' than most.

 

 

Won't be disappointed by any input...and i might learn something.

HH, Zincoln

[oldmancoyote1]

Can't tell from the photos.  I think I see some cubic forms.  If so, it may be pyrite.  Crush a small piece.  If it crushes to a powder, pyrite is most likely.  If it  deforms like lead, it's likely gold.

[Zincoln]

6 minutes ago, oldmancoyote1 said:

Can't tell from the photos.  I think I see some cubic forms.  If so, it may be pyrite.  Crush a small piece.  If it crushes to a powder, pyrite is most likely.  If it  deforms like lead, it's likely gold.

oldmancoyote - as mentioned, when i crushed a piece it flattened out nicely and held together. Not pyrite.  Strong suspicion its a gold/silver/? compound.  THank you.

[GotAU?]

Looks intriguing! Is there a scrap metal or goldsmith/gemology lab in your area that can use a XRF gun to analyze it?

[Zincoln]

i know of one an hour away....but will be asking some shops in my area this week to see if someone has access.

[GotAU?]

10 minutes ago, Zincoln said:

i know of one an hour away....but will be asking some shops in my area this week to see if someone has access.

It may be expensive though, see if there’s a Prospecting club in your area that has members who know what they’re doing, they might be able to help out.

[mn90403]

4 hours ago, Zincoln said:

i know of one an hour away....but will be asking some shops in my area this week to see if someone has access.

Whenever I have a 'what is it' I go to a local coin dealer/gold buyer and they gladly shoot my material and write me an offer if it is precious metal.  I think they are 'fair' with their offers but I haven't sold anything to them yet.  I have bought some of their gold coins in the past.  They know that is part of their business and service is to make lots of shots with their gun which has now turned into a table model and make lots of offers and sales take place.  You will never get a good offer from someone who doesn't know what they are buying.

I hope you have gold and silver there.

[Valens Legacy]

You have some nice looking samples that I believe to be gold. Almost any gold dealer could do an acid test to let you know if it is gold.

Some of what I see looks like it may have a high silver content, but gold none the less.

[Gerry in Idaho]

Zincoln, A couple pics looks pretty gold to me.  I hunt Eastern Oregon quite a bit and we find pocket specimens and placer nuggets.  Were you detecting Ore Dump piles?  The pic with the red background looks pretty assuring as well as the pic with the dime.  There's a Geologist in Baker City (if he's still around) who will verify or your next trip to Boise and I can verify.  Yes they sometimes have a silver look to them.

[GB_Amateur]

I'd say you've done a good investigation.  Specific gravity test on the original chunk (probably too late for that...) and on one of the purest pieces would likely shed some light.  Conductivity test with an ohm-meter (multimeter) is another easy test.  If you had a PI with adjustable delay, that might tell you something.

But it's hard to beat an XRF spectrum when done by a competent technician.  If you had more of it, an assay would make sense, of course, but I doubt that is cost effective for one piece.

50k(?) question:  can you go back for more?