Englebright Dam is THE riffle in the (river is the suicebox) of the south fork of the Yuba for 70 years 1941 ref

http://www.fishsniffer.com/maps/englebright.gif

http://upload.wikimedia.org/wikipedia/commons/d/d7/Gold-crystals.jpg

No results found for "specific gravity of gold bearing chemicals". on Aug 3,2011???

There is an old and known association between pyrite and gold.
Pyrite is found in, or associated with,
more than 70% of the world's gold deposits."

Gold is usually found in nature in the uncombined state in quartz veins and alluvial sands, though sometimes it occurs combined with tellurium as calaverite.

The World's Oceans contain 20 million tons of gold

Englebright Reservoir is at an elevation of 527 feet.... 528 feet during flood stage.
The 39-mile length of the South Yuba River between Lake Englebright and Lake Spaulding
Floods bring into Englebright Lake new small gold in every high water event.

Mesh refers to the openings between the threads of a screen and is measured by the number of openings per inch; that is, 10 mesh equals 10 holes or openings per inch.
10 mesh = 2.000 mm = .0787 in.
12 mesh = 1.700 mm = .0661 in.
14 mesh = 1.400 mm = .0555 in.
20 mesh = 0.850 mm = .0331 in.
40 mesh = 0.425 mm = .0165 in.
50 mesh = 0.300 mm = .0117 in.
60 mesh = 0.250 mm = .0098 in.
80 mesh = 0.180 mm = .0070 in.
100 mesh = 0.150 mm = .0059 in.
120 mesh = 0.125 mm = .0049 in.
Properly set, the sluice box can recover up to 325 MESH size gold. when Not including the lanolin sheepskin finish.

Grain gold is smaller than a troy grain-sized nugget.
Coarse gold will not pass through a 10-mesh screen.
Medium gold will not pass through a 20-mesh screen and averages about 2,000 colors to a troy ounce.
Fine gold will not pass through a 40-mesh screen and averages about 12,000 colors to a troy ounce.
Very Fine gold passes through a 40-mesh screen and averages about 40,000 colors to a troy ounce. Flour gold is even finer than Very Fine gold. It has such a large surface area in proportion to its weight, it usually cannot break the suface tension of water. It tends to float out of pans and over riffles. Color simply means a tiny particle of gold.

One mile above the, then only Hwy 49 bridge across the South Yuba, ....
circa 1988, I removed by hand shovel screens with 5 gallon buckets dumped into river powered sluice (NO ENGINES)
1oz in 1 month @ 2 hours per day play yoga labor.
@2days price, in 60 hours of labor, resulted in $1600.00 @ 24kt gold (actually 21kt)
Roughly, then, $25 per hour while respecting the enviroment and peacefully self employed!

Also that year invented the only known VERTICAL SLUICE (patent pending)
Investors inquiries encouraged.
Keywords are
Englebright Lake Gold California Placer Gold $1600 oz 2011 investors no cleanup Vertical Sluice Patent Pending
Many gold placering sluices operated at a 1 inch drop per foot of fall.
This level of turbulence keeps very fine gold suspended and so is "lost".
Lanolin placed on fiberous sheep skin, rugs etc, can retain some very fine gold as it sorts from a different set of forces.
That mechanism would follow the upper normal sluicing in a secondary, finer screened and slower water flow environment.

Wikipedia: Arsenopyrite also can be associated with significant amounts of gold. Arsenopyrite specific gravity 6.1 heavier than magnatite and hematite.
Quartz specific gravity 2.65.
Magnetite specific gravity 5.17–5.18
Hematite specific gravity is 5.3
Zirconium specific gravity 5.6 - 6.0 = 5.8

Gold is difficult to dissolve out of rock or minerals. The original source of the gold is unimportant, ranging, as it does, from mesothermal lode deposits to massive sulphide deposits to disseminated sulphides in bedrock to pre-existing placer systems. Placer deposits depend on an original pre-concentration of gold which can be liberated through weathering. Eluvial, or residual, placers are a type of placer deposit in which gold has undergone little transport and actually formed on, or near, the original source through the weathering or erosion of host rock. Owing to its relative chemical inertness and its density, gold remains behind while the surrounding material is removed, essentially concentrating the gold in the weathered remnants.

The gold is bonded in the magnetite, hematite, limonite, or other iron minerals that make up the black sand.

Mesothermal gold deposits, which form at temperatures above 350°C, occur along large breaks or faults in continental crust. The origin of these is not certain, but they form at depths of 3 to 5 kilometres below the Earth's crust, and appear to be associated with the upward migration of fluids from the Earth's mantle." These are deposits often associated with thrust faults and collisional tectonics where fluids over 350°C could interact with the rocks and deposit gold.

Negatively-Charged Metallic Salts

Aluminum -1.71 volts
Zinc -0.76 volts
Iron -0.44 volts
Cadmium -0.40 volts
Indium -0.34 volts
Cobalt -0.28 volts
Nickel -0.23 volts
Tin -0.14 volts
lead -0.12 volts
Hydrogen -0.00 volts

Positively-Charged Metallic Salts

Copper + 0.52 volts
Ruthenium +0.49 volts
Palladium +0.62 volts
Rhodium +0.68 volts
Mercury +0.78 volts
Silver +0.80 volts
Platinum +0.90 volts
Uranium +1.01 volts
Iridium +1.02 volts
Gold +1.36 volts

Averill (1946) estimated that, under the best operating conditions, 10 percent of the mercury used was lost and, under average conditions, the annual loss of mercury was up to 30 percent. Mercury use varied from 0.1 to 0.36 pounds per square foot of sluice. We estimate that a typical sluice had an area of 2,400 square feet and used up to 800 lb of mercury during initial start-up, after which several additional 76-lb flasks were added weekly to monthly throughout its operating season (generally 6 to 8 months, depending on water availability). Assuming a 10-30 percent loss, the annual loss of mercury from a typical sluice was likely several hundred pounds during the operating season. From the 1860s through the early 1900s, hundreds of hydraulic placer-gold mines operated in the Sierra Nevada. The total amount of mercury lost to the environment from these operations may have been 3-8 million lb or more, from estimates by Churchill (1999) that about 26,000,000 lb of mercury were used in California. Historic records indicate that about 3 million lb of mercury were used at hardrock mines in stamp mills, where ores were crushed. Mercury was also used extensively at drift mines and in dredging operations. The present distribution and fate of the mercury used in historic gold mining operations remains largely unknown, and is the focus of ongoing studies.

vials http://ny-image2.etsy.com/il_fullxfull.240982606.jpg

Core drilling in May and June 2002....thirty holes were drilled at 7 different locations along the longitudinal axis of the reservoir, recovering 20 complete sequences of post-reservoir deposition and progradation. The total length of sediment recovered was 379 m, with 83% average recovery.
Englebright sediment accumulation varied in thickness and grain size: 6-8 m dominated by silt near the dam; 31 m of layered silt and sand in the middle of the reservoir, and 22 m of sand and gravel at the site farthest upstream.

http://www.microwavegoldkiln.com/smelting_tips

Roasting Your Concentrates: Here’s a suggestion from us and a couple of GPK users that can help with some types of black sand concentrate and is absolutely necessary for sulfide and partially oxidized ore concentrates. Remember: the less junk in your crucible, the easier it is to smelt out your precious metals from the concentrates and the better your flux will work during the smelting process. You need a metal gold pan and a propane fired type stove burner to accomplish this roasting step.

Put your metal gold pan on your propane burner and turn the burner up on high. Spread a thin layer of your black sand in the metal gold pan and heat it up. Stir it occasionally and keep roasting it until it stops smoking and smelling. Obviously, this needs to be accomplished outside in good ventilation and you need to stay the heck out of the smoke and the fumes coming off the roasting concentrates. Don’t worry; your gold is not going anywhere, unless the wind is blowing about 40 miles an hour - then everything is going away. Once the concentrates are roasted, let the gold pan cool off and put your roasted concentrates in a suitable container. When you have enough of the roasted concentrates, you can then smelt them as outlined in the instructions. These steps can really enhance the effectiveness of the smelting process. Even if you don’t “grind” your black sand, the roasting step will definitely help your recovery. Another benefit of the “grinding” process is that it will help increase the homogenous mixture of your black sand with the flux that is necessary prior to microwaving it. If your mixture is not homogenous and there is an excess of black sand contacting your crucible during microwaving, a phenomenon I call a “thermite type” reaction can take place and burn a hole in the side of your crucible. Not a good situation to say the least; the finer your black sand is the better.