What is placer gold

Disinfectants, aspirin, fungicides, bandages, and similar items should be included. For areas of considerable sunshine, tanning lotion, sunglasses, and a hat are needed, and salt tablets should be taken as designated to prevent heat prostration. Wearing a safety hardhat and safety glasses may be advisable at times. Panning for Gold The standard gold pan is made of stiff sheet iron and is 35cmin diameter at the top and cm deep.

The rim is flared outward at an angle of about 50 degrees from the vertical. Smaller pans are used for testing, and it is advisable for most panners to use either a cm size for handling ease. Probably the 1. Frying pans or other cooking utensils may also be used for washing out gold but are less effective.

Before any kind of container is used for panning it should be cleaned thoroughly and all grease should be burned out. New pans generally are greasy and should be heated over a fire until this coating is gone. Even a rusty pan, if clean, can be used satisfactorily. In fact, the roughness due to the pitting of the rust may assist in holding back the gold.

There are different techniques and subtle variations in the art of panning--experience teaches which is best. Those with wide experience and much practice can recover the most gold with the least effort. It is sometimes said that good panning technique lies in the action of the wrists. After much practice the good panner should be able to save even the very fine gold that may be nearly but not quite free from the black sands. The pan usually is filled level with the top, or slightly rounded, depending somewhat upon the nature of the material being washed and the personal preference of the panner.

It is then submerged in water. Still water cm deep is best. While under water the contents of the pan are kneaded with both hands until all clay is dispersed and the lumps of dirt are thoroughly broken. The stones and pebbles are picked out after the fines are washed off. Then the pan is held flat and shaken under water to permit the gold to settle to the bottom. The pan is then tilted and raised quickly -- still under water -- so that a swirling motion is imparted and some of the lighter topmaterial is washed off.

This operation is repeated, occasionally shaking the pan under water or with water in it until only the gold and heavy minerals are left.

With proper manipulation, this material concentrates at the edge of the bottom of the pan. Care must be taken that none of the gold climbs to the lip of the pan or gets on top of the dirt. Nuggets and coarse colors of gold can now be picked out readily with a tweezer or with the point of a knife. Cleaning the black sand from the finer gold is more difficult, but can be carried nearly or entirely to completion by careful swirling of the contents as described above, always watching to see that none of the colors are climbing toward the lip.

This part of the operation usually is done over another pan or in a tub so that if any gold is lost it can be recovered by repanning.

The concentrates should be dried, and the black sands composed largely of magnetite can then be removed by a magnet or by gently blowing them on a smooth flat surface. If there is an excessive quantity of black sand, the gold usually is amalgamated by putting a portion of a teaspoonful of mercury in the pan.

In sampling work, extra care should be taken to see that no fine colors are lost. When mining, however, additional time needed to insure that all colors are saved probably is not justified because the value they add is so small. A word should be said here about other minerals that you may see in your gold pan. Pyrite "fool's gold," an iron sulfide and mica are often mistaken for gold by the novice.

Pyrite, which is usually a brassy yellow to white color, will shatter when struck with a hammer and becomes a black powder when finely ground. Mica, which may have a bright, bronzy appearance, is distinguished by its light weight and flat, platy cleavage. Both minerals are common in gold areas.

Other minerals that will collect with the gold and black sands because of high specific gravity include ilmenite iron-titanium oxide , hematite nonmagnetic iron oxide , marcasite an iron sulfide , rutile titanium oxide , scheelite calcium tungstate , wolframite iron, manganese tungstate , tourmaline boron and aluminum silicate , zircon zirconium silicate , chromite iron and chromium oxides , and cinnabar mercury sulfide.

If present in sufficient quantity, these latter minerals may have some economic significance, although efforts to recover them as byproducts are seldom worthwhile. Native platinum, elemental mercury, lead shot, and similar materials are also occasionally found in the pan. This question becomes more difficult to answer as the size of the planned operation increases.

Estimation of the amount of gold recoverable and the overall costs of investment and mining is no simple matter and calls for highly experienced engineering skills for any moderate- to large-scale project. Elaborate procedures of sampling and evaluation cannot be followed by the small-scale operator because of the cost. Thus, his decisions must be based on a variety of factors, not the least of which is intuition. Needless to say, many mistakes have been made, with much resultant waste of money and effort.

Do not let what started out as a recreational activity become your master instead of your servant. Sampling Techniques Many methods of sampling are possible, including the simple panning of gravel from surface exposures, churn drilling, test pitting and trenching, shaft sinking, and drifting.

As an aid in tracing possible gold-bearing channels, geophysical techniques have been employed with some success, but proper use of the typical instruments involved is generally reserved to experts.

Moreover, interpretation of results is seldom adequate to provide any quantitative estimates, although the information gained can be useful in planning an exploration program. Panning and rocking described later are the basic means of determining the recoverable gold content of placer materials.

A fire assay, sometimes made on a concentrate, provides a relatively complete estimate of the gold content of the material, but a poor estimate of how much gold can actually be extracted by conventional washing methods. Thus, placer gold is seldom assayed, exceptto determine its fineness measure of gold purity. In estimating the value of gold in the pan after washing a quantity of gravel, the technique of counting nuggets and "colors" is normally followed.

Generally, pieces worth more than 50 or cents are considered as nuggets; smaller particles are colors. When skill is developed in estimating the various sizes of particles, a good degree of consistency can be achieved in the results. Where samples can be obtained across a section of the bank exposed along a creek, it is good practice to cut a vertical groove or channel of fairly consistent width and depth.

The sample may be cut from top to bottom, or in segments comprising several different samples if the bank shows distinct changes in materials. Bars may be sampled by digging a vertical hole, clear to bedrock if possible, and panning the product. For surface mining of "skim bars," sampling consists of simply taking a panful from a favorable point and visually estimating the amount of similar material in the vicinity.

Clearly, there is not much accuracy in any of these methods, but the deposition of gold in such locations is bound to be erratic anyway. More representative sampling is usually possible in the larger deposits where deposition and size of gold particles is more uniform or consistent. Calculating What You Might Have For the small-scale miner, sampling will usually be limited to taking a panful here and there and possibly running a larger sample through a rocker or sluice if panning discloses any gold.

If colors are found, a record should be made of the number and estimated size of colors per pan and the approximate location. The sampling then progresses until one is assured the prospects are good enough to warrant a mining operation of some sort. Differing fineness or price will affect the values somewhat.

It is common to report panning results in cents per pan. So, assuming you have determined that a "pan factor" of about pans per cubic metre bank measure for the 30cm pan is a suitable figure, multiplying the cents-per-pan figure by gives the estimated value per cubic metre. Another means of estimating is to rank the colors into three groups, as follows: Number l: colors weighing over 4 milligrams Number 2: colors weighing between 1 and 4 milligrams Number 3: colors weighing less than 1 milligram Note: 31, milligrams equals 1 troy ounce.

Scales will be needed to check the weights until the eye can judge the sizes properly. It is recommended that particles over 10 milligrams be weighed individually. A rough measure of value is one-tenth of a cent per milligram. Thus, the value in a pan can be calculated using your visual count and tally of the number of colors of each rank. After sufficient practice, good estimates will come easily. Thickness has a great bearing on weight: For instance, some gold might look large, but actually be flat, flaky, and hence very light.

Determining the overall value of a deposit with any accuracy calls for a knowledge of accepted practices and mathematical procedures for weighting the values and sample intervals. It is important also to understand the statistical principles of variation and distribution, which are beyond the scope of this report. Generally, the practical prospector will take a few measurements,make some crude calculations using his panning results, and decide to stay or move on. How To Go About Mining When a site where gold is known to occur has been found, and after it has been sampled and judged worthy of further effort, the ownership status should be checked to assure that the ground is open for claiming.

Then, after staking adequate claims or arranging to lease if the ground is not open to claim , you are ready to consider mining. Whether mining permits are required should be investigated, because placer operations of any size may drastically change the local water quality. A simple operation may have virtually no effect on a stream or surroundings, but when materials amounting to more than a few cubic metres a day are handled, the possible effects begin to become significant.

Choosing a Recovery Method Among the simpler hand methods of recovering gold are the gold pan, the rocker, the dip-box, thelong tom, and the sluice. Panning has been described in a previous section, entitled "How to Look for Placers," and will only be discussed briefly here. The pan is generally too slow to be effective for anything more than prospecting. The rocker is a time-honored device of the small-scale miner with limited means.

The dip-box and long tom might be considered more like simplified sluicing methods than distinct methods in themselves. As a method, the long tom has never been very popular but is described here for its possible historical interest. Other methods used in specific circumstances would include the surf washer, the dry washer, and skindiving.

Limited mechanization is sometimes practical for moving and washing gravels in even the smallest operation, and this possibility should not be overlooked. Even motorized devices for panning are marketed by several manufacturers.

Pumps and small excavators can often be adapted to the small mining operation by the enterprising miner. The more complex methods, such as ground sluicing, hydraulicking, drift mining, excavation using powered equipment, and dredging, require considerable investment, knowledge, and experience; a full discussion of these methods is beyond the scope of this report.

The choice of method depends primarily on the scale of operation and the availability of water. These and other characteristics of the different methods are discussed below. Gold Pan Panning is the hardest way to wash gold from placer gravels, but it is an inexpensive and completely mobile method.

A person can dig with a pick and shovel much faster than he can pan the material dug, so it pays to treat only the highest grade products by panning once one has settled down to mining. A level-full, standard 30cm pan might contain roughly 22 pounds of dry bank gravel; there are approximately to pans per cubic metre of gravel.

More than twice as many 30cm pans would be required per cubic metre. The top dirt or cover is usually cast aside and the few centimteres of material directly above bedrock and the material scraped from crevices is panned. Places to look and the proper panning technique have been covered in earlier sections. Rocker At least twice as much gravel can be worked per day with the rocker as with the pan.

The rocker or cradle, as it is sometimes called, must be manipulated carefully to prevent loss of fine gold. With the rocker, the manual labor of washing is less strenuous, but whether panning or rocking, the same method is used for excavating the gravel. The rocker, like the pan, is used extensively in small-scale placer work, in sampling, and for washing sluice concentrates and material cleaned by hand from bedrock in other placer operations. One to three cubic metres, bank measure, can be dug and washed in a rocker per man-shift, depending upon the distance the gravel or water has to be carried, the character of the gravel, and the size of the rocker.

Rockers are usually homemade and display a variety of designs. A favorite design consists essentially of a combination washing box and screen, a canvas or carpet apron under the screen, a short sluice with two or more riffles, and rockers under the sluice.

The bottom of the washing box consists of sheet metal with holes about 1. Dimensions shown are satisfactory but variations are possible. The bottom of the rocker should be made of a single wide, smooth board, which will greatly facilitate cleanups. The materials for building a rocker cost only a few dollars, depending mainly upon the source of lumber. After being dampened, the gravel is placed in the box, one or two shovelfuls at a time. Water is then poured on the gravel while the rocker is swayed back and forth.

The water usually is dipped up in a simple long-handled dipper made by nailing a tin can to the end of a stick. A small stream from a pipe or hose may be used if available. The gravel is washed clean in the box, and the oversize material is inspected for nuggets, then dumped out. The undersize material goes over the apron, where most of the gold is caught. Care should be taken that not too much water is poured on at one time, as some of the gold may be flushed out.

The riffles stop any gold that gets over the apron. In regular mining work, the rocker is cleaned up after every 2 to 3 hours, or oftener when rich ground is worked and gold begins to show on the apron or in the riffles.

In cleaning up after a run, water is poured through while the washer is gently rocked, and the top surface sand and dirt are washed away. Then the apron is dumped into a pan. The material back of the riffles in the sluice is taken up by a flat scoop, placed at the head of the sluice, and washed down gently once or twice with clear water.

The gold remains behind on the boards, from which it is scraped up and put into the pan with the concentrate from the apron. The few colors left in the sluice will be caught with the next run. The concentrate is cleaned in the pan.

Today, a hard days of digging on a rich gold-bearing river might produce a gram or two of gold, a far cry from what the old-timers could find. Placer gold is a term that refers to gold found in a secondary deposit.

Usually gold occurs in lode deposits. However, the weathering of the hard rock and action of rivers and even glaciers in some places have carried the fine gold nuggets and particles and deposited them somewhere else away from the original lode deposit. Usually, these new deposit is somewhere near the surface and in most cases along river beds or in creeks. The gold found in these secondary deposits is what is termed as placer gold. Placer gold deposits are usually not far off from where lode gold deposits are.

The gold in hard rock is released during the weathering process and then it carried off by glaciers or running water streams, rivers, flood water to someplace where it is deposited and concentrated in a placer deposit.

Because gold is relatively heavy, it is generally not carried far from the source. This means that prospecting rivers and waterways around areas where lode deposit has been found can result in the discovery of gold.

In addition, ancient river channels in places with gold-bearing rocks and flooding outwash in such places may also contain placer gold. The most common places to find placer gold is on the river beds.

However, when a large storm hits the area causing rivers and streams to flood, the runoff water run faster carrying with it lose gold particles and nuggets into the streams and rivers. Sometimes a river or stream flowing over a gold vein may eventually cut deep enough to erode the vain and carry off lose gold particles and nuggets downstream. Gold being heavy than all the other materials being carried downstream exerts a downward force on the water and quickly settles on the riverbed once the water slows down.

Find out how the Gold Rush Nugget Bucket works to recover find gold! Date October 20 Written By David Hylsop. Comments Comments. The orderly piles of waste rock the dredges left behind as they moved across the landscape are called tailings. In order to capture as much gold as possible, dredge operators and small-scale placer miners alike added mercury to their sluice boxes because gold and mercury bond chemically to form what is called an amalgam.

After removing the riffles and scraping the amalgam out of the box, the process of retorting can begin. Retorting involves heating the amalgam in a crucible until the mercury vaporizes; then the gold can be melted to remove impurities and poured into a mold to create a gold brick. Placer miners using a small steam boiler and drift mining techniques on the Charley River, s. Yukon-Charley Rivers National Preserve was created in part to protect and interpret the history of the Klondike- Alaska Gold Rush and the legacy of gold placer mining in the region.

From the air over Coal Creek and Woodchopper Creek they will also see gold dredges and the neatly piled tailings that are the telltale sign of a dredge mining operation. The Coal Creek dredge. Last updated: April 14, Stay Connected. UAF Archives, George King Collection No machinery was needed save the simplest tools; no organization was required, beyond a willing partner; no capital, save muscle.