Gold occurring in quartz veins?
 

I'm not a geologist by any means, but I've gathered from my research into the gold mining industry that gold is often found in quartz veins. My question is whether or not all quartz veins have the potential to contain gold, or is it more of an anomalous occurence? The reason I ask is because I live along the coast, and a lot of the outcroppings around here are streaked with quartz veins. Is it worth my while to get a rock hammer and try to pick away at the quartz in the hopes of finding any traces of gold? Thanks for any input.

Re: Gold occurring in quartz veins?
 

Excellent question, MinedGames.

http://www.goldfun.com/Geology/Gold_...artz_veins.htm

Re: Gold occurring in quartz veins?
 

Quartz is "silica", the most common mineral in the world. All of the brown sands a person sees along waterways and lake shores is silica; ground up and stained (by other minerals over time) quartz.

Basically....
When the earth's crust cooled it contracted. The result was that multitudes of fisures, cracks, and "stringers" (finger cracks running all different ways off of the larger cracks. Anyway, the molten center of the earth below the crust is comprised of liquified forms of minerals some 2500 degrees (F) coupled with water vapor that creates tremendous pressures. Several billion years ago the pressure forced the molten (liquified) minerals up into the crevices, cracks, and stringers in the crust where they cooled, solidified, and became the "veins" you are talking about. Since silica (quartz) is most common among minerals it frequently was the primary molten mineral that filled the open spaces in the crust.

What is important to a prospector is that in it's liquified form, silica has the inate ability to trap and hold other minerals. Thus as pressure forced silica to flow into the cracks, it carried many other minerals in company. Microscopic liquified particles of gold and other minerals were also carried up into and through the crust in other "host" minerals (rock). One of the minerals was gold, which is comparatively rare but also one of the most widely distributed over the earth.

Over billions of years after the atmosphere was formed, tremendous erosion, deterioration, and other changes (i.e. shifting plates that rise and sink over time) have occured on the surface. To get a sense of the great amount of erosion that's taken place over the billions of years, a person only needs to look at the Uwharrie Mountain range in the piedmont area of NC (in the U.S.). A topo map today reports just large hills...maybe 800-850 feet at the most in elevation. Geologists believe they are the oldest mountains in the U.S. and estimate that at one time they ranged to more than 20,000 feet in elevation.

As the surface of the earth's surface has eroded it has lowered in elevation and in this process areas of many quartz veins became exposed to the effects of weathering and other natural occurances. Areas of veins near the surface decomposed. As quartz carrying gold broke down, the gold became free of it's natural solidified "host" and is what is called "placer" (the "a" is pronounced like the "a" in "platter") gold. This freed gold is what throughout history and today, is primarly sought by prospectors. Gold that is still in it's rock matrix (host) is called "load" gold, and the matrix (vein) that carries it is called a "load"...as in the "mother load" that the old timer prospectors talked about and sought.

There are probably millions (and maybe more millions) of quartz veins. Of the total number VERY few carry gold, and by far most of the ones that do hold microscopic particles invisible to the eye. Too, much of these particles are "non-free milling". That is they are in chemical combination (or chemically bonded) with other minerals...kinda like stiring and disolving sugar in a glass of hot water. The sugar is there but you can't see it or pick it out.

Gold particles that are said to be "free-milling" chemically exist by themselves and can be spearated from materials in company by water-gravity action such as that which is utilized when using a gold pan. Gold particles that are not free-milling have to be separated out with chemicals like arsenic, and is a very expensive and involved process.

Most of the veins that carry gold (chunks of the quartz or other rock are called "ore") do not contain enough gold per ton to make it economically feasible to process it.

A way a person can tell if a vein (or it's "outcropping" which is chunks of the vein that are laying on the surface of the ground where the vein has become exposed and is deteriorating) contains gold, is to firstly pulverize pieces of the rock picked up from different areas of the load, and then pan it out to see if the load contains visable gold. If it doesn't, then a person has to take a number of samples (again from different areas in the vein) and have them "assayed", or processed to separate out the gold if it's present. If there's gold in the vein then it becomes a matter of two critical questions: (1) how much gold is present (how "rich" is the vein or load) i.e. how many oz. of gold on average, are there per ton of ore) and (2) is the gold free-milling or non-free-milling?

These two questions tell a prospector if the vein is worth working, and whether or not it's a vein that the prospector can start working, initally using a simple and cheap pick & shovel operation, (free-milling gold)...or whether a whole lot of money for a comparatively large operation has to be generated (non-free-milling) to recover the gold.

I hope this helps. Best of luck engaging in "the great chase". And if you find a good deposit I need to know where you're diggin!

Re: Gold occurring in quartz veins?
 

Thanks for the replies, guys. I particularly appreciate your post Goldminer, as it obviously took some time and effort to compose.:coolbeer:

Re: Gold occurring in quartz veins?
 

You're quite welcome. I type about 65 words a minute so there isn't much time or effort posting.

Re: Gold occurring in quartz veins?
 

Very informative and interesting nevertheless.

Re: Gold occurring in quartz veins?
 

Well, if your quartz veins look exactly like this photo, please send me a PM, and I'll do what I can to help.

Chris

http://nevada-outback-gems.com/Refer...old_quartz.jpg

Re: Gold occurring in quartz veins?
 

I'd say the vein that these ore chunks came from has some distinct possibilities...maybe even worth excavating?

Can you imagine how many microscopic particules of liquified gold happened to have located together in this portion of liquified silica, in order to have formed this nugget when everything cooled and solidified? More than 50 eh?

This is why nuggets are rare. There are more diamonds found than gold nuggets.
P.S....if you don't know it, prospectors call all pieces of native gold "colors"; each particle is a "color" regardless of size. Five pieces of gold in a gold pan are 5-colors.

And a "nugget" is defined as any color that won't pass through a 10-mesh screen (10-holes per linear inch). The window screen normally seen in houses is about 18 or 19-mesh.

Re: Gold occurring in quartz veins?
 

Gold and silver veins typical occur in high temperature hydrothermal out crops. If you find a vein in such an environment your chances of finding allot of different minerals is going be high. My experience has alway led me to creeks. Creeks are your best bet for finding out crops. Surface soil will hide potential rock out crops. http://www.mathandstuff.freeservers.com/

Re: Gold occurring in quartz veins?
 

Good general rule of thumb.............

"Gold is almost always associated with quartz, but quartz is not always associated with gold."

Your prospects START with quartz.......

This applies obviously to "in situ" or gold within its original matrix. Once dealing with alluvial or eluvial (water or wind) erosion such as placer deposits, the quartz may be present only in the form of smaller inclusions within "free" fines or nuggets.

Re: Gold occurring in quartz veins?
 

If you're going to prospect waterways, first look for black sands. You can find black sands and no gold but will seldom ever find gold and no black sands. This is because gold occurs most often in geographical areas that are highly mineralized. Black sands are actually a very dark brown but appear coal black when wet. They are comprised of iron ores and oxides...among others: magnetite, hemitite, and ilminite.

If you want to find gold for sure, work the watersheds in areas where gold has been found in the past. It's still there and it's easy to find. There is a lot of it out there but it's scattered. The challenge is finding concentrations (deposits) rich enough to make them economically feasible to work.

Re: Gold occurring in quartz veins?
 

I have attached a photo of something I came across in the remote Canadian Cariboo Mountains. Does this look like it might contain gold????

How would I know?

Any thoughts would be appreciated!

Re: Gold occurring in quartz veins?
 

Is the area know for previous mining activity? The rock looks as if it has been removed within the last hundred years. The iron oxide coating is plus but look for a green coating because it signifies gases high in nickel. I would get a hammer and cracking. If you could find pyrite that is not green but silver or gold in color or galena (lead sulfide) you could be getting close.

Re: Gold occurring in quartz veins?
 

The Cariboo region hosted the gold rush, and Barkerville is also in this region

I will look for a green coating coating next time I am up there....its quite a trek....hours from the nearest town, and then water access only....

This quartz runs from the beach up the hill for about 25 feet before disappearing under the ground....its about 5 feet wide, and looks like it has never been disturbed....

Re: Gold occurring in quartz veins?
 

If you can legally prospect the land, break some pieces of the quartz off at different places, use a mortor and pestle to pulverize them, and the pan the materials looking for gold.

If you don't see any gold then take other samples from different areas of the vein and send them off to an assayer. This way you'll know for sure.

Re: Gold occurring in quartz veins?
 

That looks real good. Firs thing I would do is pan the gravel as a test and see what gold is there.


Chris

Re: Gold occurring in quartz veins?
 

Thanks for the tips, Ill do that next time I am up there.

I cant wait. It is a huge quartz run....IF there is gold in there, wow!

Ill be getting the pick, shovel, hammer, and pans ready to go!

I will take more pics and update this thread when I go.