Moore Creek Specimen Cut in Half

[Steve Herschbach]

Hi,

This 1.5 oz Moore Creek specimen looked like a round rock with just a bit of gold showing. The weight made it obvious it contained a lot of gold, and so it was sliced in half. Revealed is a dense web of dendritic gold dispersed evenly throughout the interior of the specimen.

The quartz is quite solid, and in fact I sold the piece to a gentlemen who sliced it up some more and polished it up. Although the quartz in not the pure white demanded by jewelers he made a very nice and unique pendant from the piece.

Here is another shot with the light reflecting off the gold:

It makes me wonder how this stuff was deposited. The recent article by Chris Ralph in the ICMJ talks about gold being deposited last and filling cavities left in the quartz. That certainly fits for most gold in quartz I've seen. But this stuff would have to have been remarkably porous quartz for that to be the case.

Then there is George's spectacular specimen found at Moore Creek. It has more gold than quartz and the quartz is of a coarse "surgary" texture. Did the gold and quartz form at the same time?

It would be interesting to take something like this and dissolve the gold out. Would the quartz hold together or fall apart? Or conversely, if the quartz were dissolved out, would you end up with a gold sponge or discrete pieces of gold? Which is holding the other together? It might help reveal which came first.

Another one I'll have to try and get a picture of is a nugget a friend found at Ganes Creek. It was solid gold, with a few crystal clear beautifully formed quartz crystals imbedded in the gold. Almost like you had molten gold and tossed in a few crystals and stirred it up. It looks totally as if the crystals grew inside solid gold.

Heck if I know the answers but there is some complicated stuff going on inside the earth!

Steve Herschbach

Moore Creek Mining LLC

[kcoulson]

That is a very nice specimen Steve. I can see how it would make a nice piece of jewelry.

Ken

[Steve Herschbach]

Hi Ken,

Moore Creek has quite the variety of specimens for sure. Some are pretty and some are just "rocks with gold in them".

Here is another Moore Creek specimen. This one started out at just over 5 ounces. Again, gold was poorly exposed on the surface. I ground it down evenly until gold was exposed on all surfaces and got it halfway polished. Final weight is 2.8 oz (yes, I got a bunch of gold panned out of the grindings).

This piece is interesting since it is a rather clear, crystalline quartz instead of your normal opaque quartz. It gives the piece a unique translucence that lets you actually look into the quartz and see gold beneath the surface. And again, the typical Moore Creek dendritic type structure.

Steve Herschbach

www.moorecreek.com

[fredm]

Steve polishing those species sure improved their appearance...I may have to slice my little specie and see what potential is there..it is an interesting piece but not pretty......

I got the washers, thanks!!!

Fred

[Reno Chris]

Sure looks like the gold in that first nugget grew first and then the quartz later grew and surrounded it. Probably the same with George's nugget. Steve, I think with the dendritic growths, there is little doubt the gold had to grow first and the quartz later surround it.

On the other hand I've seen lots of gold from other locations where the gold seems to fill cracks and voids left between the quartz - that stuff seems to have had the gold laid down after the quartz was in place (however none of those pieces are from Moore Creek).

The gold being deposited last after the vast majority of the quartz has already been laid down is the norm for many gold deposits, but there certainly are exceptions. Moore Creek seems like it would be one of them.

There is little question that Moore Creek has some unusual gold-quartz relationships as there is almost no vein quartz at all. Moore certainly is one of the lowest quartz gold deposits I have ever seen. The only ones I can think of with less quartz occur in limestone areas where there is no quartz or silica in the surrounding country rock either. The shale country rocks around the Moore Creek deposit has silica and quartz as does the granitic igneous intrusive rocks. Why there is so little vein quartz at Moore is a very interesting question and perhaps the coming exploration will give us some more answers. 2008 should be a really exciting year at Moore Creek.

Chris

[Ted Scott]

Very interesting post Chris.

Nice gold Steve.

[eodseal2000]

That's awsome, thanks for sharing!

[Miner Matt]

I have another take on this. Let me first say that not examining the gold first hand it might be hard to tell.

But in my area gold forums like that when calcite is present. What happens is the calcite forums.

Then the quartz and in this process the calcite is later dissolved by water or some other occurrence. The gold then fills the cavity's left by the calcite.

Do you have limestone in the area?

In one mine I have. I have to muck out the tunnel the same day I blast. If not the calcite will lock up the muck pile and I am not able to load it in the cars. Just like concrete. This sucks because of the possibility of a hang fire.( A stick of TNT not going off with the rest )

It is in this mine that the gold forums like the stuff you have cut.