History & Geology
Quartz: The Indicator of Gold
The largest and most perfect single gold crystals are nearly always in the form of octahedra. These large octahedral crystals often possess deeply recessed faces.
Gold, on the other hand, is super rare, and is one of the rarest elements in the earth’s crust. It averages only 0.000004 percent of the earth’s surface. That is four parts in a billion.
I have been finding nuggets all my life, beginning in Sierra County 50 years ago, and believe me they don’t pop up out of the ground like mushrooms when they see me coming and say, “Here I am and take me home.”
Let’s examine why your placer gold looks the way it does and what you can tell about its journey based upon its appearance.
Gold on the bedrock is a good rule of thumb, but not one that is 100 percent effective. There are plenty of exceptions. So, how does a prospector recognize those exceptions?
Because the forces of erosion and gravity tend to carry lighter materials like quartz away more easily, the heavy minerals like gold or silver will tend to be concentrated in the general area around the vein outcrop. These concentrations are what make residual placers so attractive.
To add to the confusion, the dam wasn’t holding back a large amount of water. It was full of gravels and had a small creek running through it. I had to know more.
I didn’t know what to expect because the area we were working was not close to the water, but we were pleasantly surprised when we began to pan out some nice flakes and a few pickers.
I grew up in Southern California, and found my first nugget there, so I know my way around. Because there is good gold there, I thought it might be helpful to take a look at the many placer gold opportunities found in the southern part of the state.
These deposits are very widespread across the planet. In fact, they are so extensive that something around 75% of all the gold ever mined comes from these types of deposits (if one includes the placer deposits that also formed from them).
The interesting thing about the Mother Lode area is that we can pretty much find at least a little gold in any creek or river (and even in some of the many dry gulches).
…we focused on various layers of hard-packed flood material out of the creek, and we also obtained some material up quite a ways from the creek itself on bedrock.
This area could be re-evaluated for placer scheelite and gold potential in the future along with sand and gravel processing…