Most prospectors spend their time looking for placer gold. These are the solid pieces of gold that have eroded from a vein and have formed in a concentration. Most prospectors look for placer gold in creeks and rivers (although this isn’t the only place they are found).
There’s a good reason for this. Placer gold is easier to locate than gold that is contained in a hard rock deposit. However, there are some miners that specialize in located gold within hard rock. While it is harder to find, the payoffs can be huge.
Let’s look at a few indicators that may help you locate gold in hard rock.
6 Major Indicators to Help you Find Gold in Rock
Changes in Rock Type and Vegetation
Gold will often form in places where two different types of geology come together. Thus, places where two distinctly different types of rock come together are alway worth prospecting.
If an area has a lot of soil, then these rock changes aren’t always easy to see. In this case, vegetation will be a good indicator. Different plants will generally grow in different types of host rock.
Soil Color Changes
Soil is comprised of small particles of rock and mineral, so a chance in soil color is a good indicator for gold, just like a change in rock type. Often, changing soils that are yellowish or reddish in color will indicate a high iron content, which is a very good sign in gold country.
Eroding Rock and “Rotten Quartz”
In places where different rock types come together, the contact point will sometimes have material that has a very loose structure. This rock will crumble easily. If quartz is present, it will often be very “rotten” and crumbly.
Iron staining is another excellent indicator that hard rock gold may be present. As mentioned already, reddish soils are a good indicator of this. If you are finding quartz pieces that have dark red or black attached to it, this is also a good sign that there is high iron content, and you may want to crush and sample some of the nearby rocks.
Minerals often found with Gold
There are some well-known mineral that are commonly associated with gold. They are found in gold districts worldwide. Get familiar with the types of geology in the area that you are mining.
Similar Conditions to Nearby Mining Districts
If you are exploring new spots with little evidence of mining or prospecting in the past, then it is a good idea to first look at nearby gold areas and compare geology. Sometimes you can identify similar geological indicators that can help you find gold.
Gold Ore Mining Techniques
For the average small-scale prospector, there are just a few methods that work well to locate gold in rock.
First, I always recommend that you carry a gold pan and sample the gravels in the area. Even in a desert, you can dig down into a dry wash and pack in some water to use while panning. If you are able to locate even some very fine gold, this will tell you that you are in a good area.
Second, you can collect promising rock samples and crush them up to release any potential gold. We detail this process in this article. It is a relatively simple method, and will give you an idea of what types of samples are worth collecting and processing.
Third, and perhaps the most popular method used by small-scale gold prospectors is to use a gold detector. By scanning mining tailings and ore samples with a metal detector, you can locate samples that contain visible veins of gold.
Keep in mind that not all gold is visible. In fact, some of the biggest mines in the world process gold that is not visible and therefore impossible to recover using the above methods.
For the average prospector looking for gold in rock, I would recommend doing you research and finding places that are likely to have large enough gold to recover.