the basic idea is to crush up goldrich ore into his fine powder as possible and then to mix it with mercury. the mercury will leech out the gold.
That is, if it touches gold it will immediately break the lattice bonds of the precious metal and form an alloy in a process known as amalgamation. A process which, when catalyzed between a dab of mercury and a sheet of gold leaf, looks like the ignition of a metallic fire in reverse.
In mines, mercury is used to recover minute pieces of gold that is mixed in soil and sediments. Mercury and gold settle and combine together to form an amalgam. Gold is then extracted by vaporizing the mercury.
The gold surface is simply "wet" by mercury and the gold is not decolorized. A tiny amount of mercury can quickly swarm across a gold surface making it appear that the color has changed almost instantly but the effect is superficial.
1. Gold is soluble in mercury, at 200 C., to the extent of about 0.06 per cent; this solubility increases to about 0.25 per cent at 1000 C., and probably decreases to zero at the freezing point of mercury.
As is well known, aqua regia (a mixture of three parts hydrochloric acid to one part nitric acid) can dissolve gold.
Both mercury and gold are very weakly diamagnetic, i.e. repelled by magnetic fields. This effect might in principle let you push them ahead of the field, but it is almost certainly too weak to work in practice.
What to do: Hold the magnet up to the gold. If it's real gold it will not stick to the magnet. (Fun fact: Real gold is not magnetic.) Fake gold, on the other hand, will stick to the magnet.
Gold and silver dissolve readily in mercury, and in the past this property was used in the extraction of these metals from their ores. The good electrical conductivity of mercury makes it exceptionally useful in sealed electrical switches and relays.
The amalgam is typically isolated by hand and then heated—often with a torch or over a stove—to distill the mercury and isolate the gold.
Mercury is commonly used in small-scale gold mining to separate gold from other minerals due to its ability to bind to gold and form amalgam.
A typical mercury-gold amalgam formed by small scale miners contains roughly 50% mercury and 50% gold. Mercury-silver amalgam formed under similar conditions however is closer to 70% mercury and 30% silver.
It is well known that at the bulk scale, aqueous mercury(II) interacts with silver metal(0) with a stoichiometric ratio of 1:2 [Eq. (1)], resulting in zero-valent mercury.
Mercury and gold form the amalgam you are seeing, and it will happen every time you spill mercury on a gold ring. It is a reaction like making a metal alloy, but it happens quickly and at room temperature.
According to the quantitative assessment, occupational mercury exposure may cause a great variety of signs and symptoms, in particular in the field of neuro-psychological disorders, such as ataxia, tremor or memory problems. However, many reported symptoms were largely unspecific, such as hair loss or pain.
Fool's gold is actually iron sulfide, a non-magnetic, inexpensive and abundant material that is a byproduct of petroleum production.
Acid test.
An acid test can reveal the karat of solid gold jewelry, but it can also show whether jewelry is solid gold or gold-plated. With an acid test, a small sample of the jewelry is removed and exposed to acid to induce a color change. The resulting colors indicate which type of metal the jewelry is made of.
In many countries, elemental mercury is used in artisanal and small-scale gold mining. Mercury is mixed with gold-containing materials, forming a mercury-gold amalgam which is then heated, vaporizing the mercury to obtain the gold.
Mercury can readily combine with chlorine, sulfur, and other elements, and subsequently weather to form inorganic salts. Inorganic mercury salts can be transported in water and occur in soil.
Pure gold on its own cannot stick to a magnet. However, if you have an alloy of gold, then it could stick to a magnet. An example of a gold alloy that may stick to a magnet is gold with over 20% of its atoms replaced by iron. In very cold temperatures this alloy of gold may magnetize all on its own.
The only way gold could truly be destroyed is through nuclear reactions. However, there does exist a way to dissolve gold using “Aqua Regia,” which is a mix of hydrochloric and nitric acids.
Chlorine is gold's worst enemy: with repeated exposure, chlorine will weaken your gold jewelry's structure and eventually lead to it breaking. Make sure to take your jewelry off before getting in a pool or spa. Cover or remove while cleaning: household cleaners with acids or abrasives will damage your jewelry's finish.
Does Coke Clean Gold? This is a handy and maybe unexpected tip, but Coke does indeed clean gold. You can dip your gold in a small bowl of Coke and make sure that it is completely covered. Leave the gold plated jewelry in the solution for 10 minutes and then rub with a soft cloth and rinse.