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Gold - From Whence It Comes


robinjojo
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The magnificent gold aurei, solidi, drachms, staters, escudos, soles and 20 dollar gold coins, to name a few, those coins whose images grace this website and auction catalogs all had their origins in the extraction of gold from in-situ, placer and lode deposits over the thousands of year that human kind sought, discovered and processed this coveted metal into coinage.

The purpose of this thread is to provide a general guide of this different types of gold deposits that were exploited by empires, kingdoms and republics to enhance their economic status throughout the ancient and modern worlds.  The photos illustrate the different forms that gold can take depending of the mode of deposit.

Placer and lode alluvial surface deposits

Gold, despite its softness, is an extremely durable native element.  In sufficient concentrations, that is having relatively little associated quartz, massive water worn nuggets can be found on the the surface of deserts and plains where rivers used to flow eons ago, or in rivers or creeks.

The  alluvial gold deposits of ancient Lydia are an example of what is probably the first effort by human civilization to extract gold for the purpose for producing gold coinage.

Gold nugget, Western Australia, 104.80 grams

This specimen is basically solid gold.  The surfaces are water worn, even though it was found in the vast desert of Western Australia.  The surface display pits or cavities in which other minerals, mostly quartz weathered away. 

855908295_D-CameraGoldnuggetWesternAustralia104.80g6-19-22.jpg.b9b9aaa05b5ac29a5849ad346ec45e85.jpg

 

Gold nugget, Western Australia, 75.02 grams

1574120256_D-CameraGoldnuggetWesternAustralia75.02g6-19-22.jpg.903a8921f00ef779e0104981158802f3.jpg

Gold found in alluvial deposits can vary in composition, as can be seen .  Australia has produced nuggets that vary greatly in weight, with some weighing a kilo or more!

 

Gold in quartz nugget, Western Australia, 120.56 grams

Here, the nugget has a preponderance of quartz, which is a light tan color due to microscopic deposits of gold.  

1278556481_D-CameraGoldinquartznuggetWesternAustralia120.56g6-19-22.jpg.7a2071170b513b025cfe3d21d4c2374e.jpg

 

Hard Rock (In-Situ) Deposits

As civilizations developed, so did the techniques used to extract gold, notably through mining and refining ore.

Here are some examples.

Electrum, Seven Troughs Mining District, Fairview Mine, Pershing County, Nevada, 13.51 grams

 1038330205_D-CameraElectrum2SevenTroughtsMiningDistrictFairviewMinePershingCo.Nev13.51g6-19-22.jpg.e8a2d41e7814bdcde6bc11379e911824.jpg

 

Native Gold,  crystalline and quartz, Coulterville, California, 51.7 grams 

116960080_D-CameraNativeGold2cyrstallineandquartzCoultervilleCA51_7g.6-19-22.jpg.dc53b31b2224e3f2099fa35740bb1ed8.jpg

 

Native Gold, crystalline and quartz California 85.58 grams

640054423_D-CameraNativeGoldcyrstallineandquartzCalifornia85_58g.6-19-22.jpg.51988ad02d84af43d98b68e98706851e.jpg

 

Native Gold, crystalline, with arsenopyrite and quartz Alleghany Co,  California, 43.23 grams

1119722003_D-CameraNativeGoldcyrstallinearsenopyriteandquartzAlleghanyCoCA43_23g.6-19-22.jpg.1b750e53e70dbdeb5ee93326d4d05872.jpg

 

Native Gold in quartz with silver telluride Hessite (dark grey areas), Old Campbell Mine, Balmertown, Ontario, Canada, 43.5 grams

In addition to quartz, gold is often associated with silver tellurides and pyrite.

1499498132_D-CameraNativeGoldinquartzwsilvertellurideHessiteOldCampbellMineBalmertownOnt43.5g6-19-22.jpg.11887f571c9ac9b7bf6093168fc5fe8d.jpg

 

Native Gold, crystalline with quartz and pyrite, Turpin Mine, Gwanda, Zimbabwe, 21.71 grams

1745690523_D-CameraNativeGoldcyrstallineandquartzpyriteTurpinMineGwandaZimbabwe21.71g6-19-22.jpg.5bdb1071995d73aa8feef4168033b1fb.jpg

 

The gold bearing ores that are more typically encountered show little, if any visual evidence of gold, even with normal hand magnification.  The specimens shown are very rich examples.

Here's a more typical example, and even this one is out of the ordinary.  This a large piece of quartz with a very small spot of native gold visible.  There might other minerals, including silver sulfide minerals.  Do you see the gold?

An old friend and retired school teacher owned a mine in the Sierra.  When she passed away several years ago, her house, two doors down from mine, was the scene of chaos.  Her nephew wanted the house emptied out quickly so it could be put on the market.  The courtyard of the house was heaped with minerals that were ultimately destined for the landfill.  I retrieved as many as I could, including this gold ore specimen, which I think came from the mine.

259364823_D-CameraGoldorespecimenCaliforniaTedi331.3g6-19-22.jpg.2edbc859a8420dec78523531ab9eae12.jpg 

 

Well, I hope this thread was informative.  Gold really is where you find it, but it does comes in different forms.

 

 

Edited by robinjojo
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  • Benefactor

Thanks!

Yes.  I was buying native gold specimens back around the late 90s to around 2000.  I haven't since then, turning more to ancients and world coins since then.

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An Australian gold nugget from the Kalgoorlie region (Western Australia), this particular mining region is known for its monster sized nuggets! But this one is only 3.64g, yet chunky. 

Nugget.png.4d46ec9d9170397c052ded72952fedda.png

And here is the nugget on top of a 70g specimen of pyrite, aka fool's gold! the colour difference is striking!

544958253_pyrite.jpg.8f344211842c47ccf50a6272b106b5b8.jpg

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40 minutes ago, Kali said:

Great specimens 😀

Usually, these kind of write-ups are just examples of found examples online, especially over on CT.

I posted a few mineral specimens on the appropriate threads on the other site and they were all mine. I know some like expat others also posted their own finds. Sorry but I don't recall seeing many internet specimens in the last 3-4 years

I thought this group had stopped the CT bashing and put that disaster behind them and moved on for the better

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1 hour ago, Alegandron said:

When I lived in NC, I panned for and found a few flake of gold. Was fun, and I have them around here someplace.

I did some gold panning in Colorado when I was very young. We ended up with some flakes but nothing worth writing home about. I'd love to find a proper nugget. 

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Also did some gold panning in the Sierra foothills, found a bit.

Also very interesting is the fact that gold is produced in supernovae and neutron stars, with the formation of heavy elements as a result of increasingly intense fusion of the gases. So all of the gold found on earth was seeded by dying stars and ended up eventually in protoplanetary nebulae that became solar systems throughout the universe.

 

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Does anyone have ore specimens from any of the classic, ancient locations, such as Laurium, Greece or from southeastern Spain, which was a major silver source for the Romans?

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"The nitrogen in our DNA, the calcium in our teeth, the iron in our blood, the carbon in our apple pies were made in the interiors of collapsing stars. We are made of starstuff." - Carl Sagan, Cosmos.

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