Gold panning is a gold mining technique used in small-scale placer mining for the sampling of a gold placer deposit. It involves using a pan to shake the heavy particles to the bottom and wash the lighter particles up to the top.

[edit] History

In the beginning of the Gold Rush, miners used rudimentary means of extracting gold from placer deposits including spoons, pots, and bowls.^[1] Some miners even used woven baskets and Chinese gold miners found cooking woks to be particularly effective.^[2] Some miners went as far as to use handkerchiefs. Another method used before panning was widely employed was a technique called dry washing. The technique was used in the mining of gold in the Sierra Nevada foothills. The idea was to take a bed sheet and have two miners hold it at both ends. Dry sand was shoveled into the sheet and wind was used to toss the sand into the air, essentially separating it from the gold. This practice was eventually abandoned and replaced with panning.^[3] Isaac Humphrey is the individual attributed with inventing and introducing the pan and rocker to the mining industry in 1848.^[4] Panning was very a labor-intensive and time-consuming process, with even the most experienced miner able to wash only 15 pans per hour. It was also physically hard on the miner, who often had to get down and hunch over in the cold water.^[5]

Even though gold panning did not prove to be the most effective technique used in gold recovery, it soon became an activity synonymous with the early days of the Gold Rush. More effective sampling devices such as sluices, rockers, and Long Toms eventually replaced panning for sampling and recovering greater amounts of gold. Today panning, using lighter and simpler pans, is still used for systematically sampling gravels upstream.^[6] It is also a popular recreational and tourist activity.

[edit] Process

A sample of gravel or overburden is taken from a placer deposit and typically run through a screen called a classifier that fits over the pan and is used to break down the gravel to a manageable size. Screening the material down makes panning the finer particles easier and faster. The material that is screened off is usually panned separately for larger gold nuggets.

About a quarter to half of the screened material is then placed in the pan that is submerged underwater just below the rim and shaken in a circular motion. The older, heavier materials such as black sand and gold settle to the bottom of the pan while lighter waste material rises to the top. This step, sometimes called stratifying, is repeated multiple times until only gold remains in the pan.^[7] A squeeze bottle of detergent is sometimes used in the final stages of stratifying the gold during panning. Adding a few drops of detergent breaks up the surface tension of the water.

Aside from conventional pans customized with a sieve or screen for classifying larger material, plastic pans designed with riffles are available for the novice.^[8]

[edit] References

1. ↑ Mining Techniques. Learn California. 2008-11-28.
2. ↑ Mining Techniques. Learn California. 2008-11-28.
3. ↑ Gold Mining in California. Brian Moore. 2008-11-28.
4. ↑ Mining Techniques. Learn California. 2008-11-28.
5. ↑ Mining Techniques. Learn California. 2008-11-28.
6. ↑ Early Gold Mining Methods. Sierra Foothills Magazine. 2008-11-28.
7. ↑ How to do Gold Panning. E-Gold Prospecting. 2008-11-28.
8. ↑ Gold Panning. Rich River Exploration Ltd. 2008-11-28.