'Aqua Regia' is a mix of hydrochloric acid and nitric acid, most commonly in a 3:1 ratio. This is believed to be the only solution known that can "dissolve" gold.
Harsh chemicals like chlorine, acids, sulfur, and salt can damage or discolor gold,1 particularly items less than 24 karats. Chlorine can weaken your gold jewelry's structure and eventually lead to its breaking.
Gold is one of the least reactive elements on the Periodic Table. It doesn't react with oxygen, so it never rusts or corrodes. Gold is unaffected by air, water, alkalis and all acids except aqua regia (a mixture of hydrochloric acid and nitric acid) which can dissolve gold.
Gold can't be destroyed unless you place it in a nuclear reactor. It can undergo various chemical reactions, but elemental gold is exceptionally stable and cannot be destroyed at a molecular level by any conventional methods.
Gold and silver both have a high melting point that should be higher than just a standard house fire temperature. But if your gold and silver bullion was in some kind of packaging as many coins are, then obviously this would melt and could damage the exterior.
Salt can be very damaging to your gold or diamond jewelry, and the main reason for this is that salt causes the metal layer of the jewelry to erode. Platinum, silver, and gold are eroded by salt, and exposure to salt over a long period of time weakens precious metals, and jewelry can break.
Gold is one of the noblest—that is, least chemically reactive—of the transition elements. It is not attacked by oxygen or sulfur, although it will react readily with halogens or with solutions containing or generating chlorine, such as aqua regia.
Real gold does not burn or get dark under heat. It simply melts: this is why it can be molded and shaped into different forms without losing its luster and beautiful yellow gold color. On the other hand, other metals like copper, iron, and brass will change color and get darker when exposed to flame.
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 (Au) melts at a temperature of 1,064° C (1,947° F).
The most useful and important vehicle for dissolving gold is aqua regia, (royal water), composed of two parts of hydrochloric (muriatic) acid, and one part of nitric (aquafortis).
Dissolving Gold
The hydrochloric acid is then used to react with the gold ions to form tetrachloroaurate(III) anions. The gold ions can then be removed from the solution which further allows the oxidation of gold. The gold is then dissolved to form chloroauric acid.
Mercury and gold settle and combine together to form an amalgam. Gold is then extracted by vaporizing the mercury. Although mercury is a naturally occurring element, it is highly toxic to humans, animals, and the environment when not handled properly.
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.
Bromine caused yellow gold to turn brown and make it brittle and prone to chemical corrosion cracking. Lesson learned: Do not wear your jewelry in hot tubs or swimming pools. Take your jewelry off when using cleaning products and never ever clean rings with bleach!
The whole point of gold is its shine. While it does not tarnish like silver, gold will over time develop a dingy, oily film from lotions, powders, soaps and the oils from your skin.
Fool's gold is actually iron sulfide, a non-magnetic, inexpensive and abundant material that is a byproduct of petroleum production.
Gold is a noble metal which is resistant to change by corrosion, oxidation, or acid. You can rub the gold-colored item on jeweller's black stone, which will leave an easily visible mark. The mark is tested by applying nitric acid and hydrochloric acid, which dissolves the mark of any item that is not gold.
We know gold is a noble metal and it lies below hydrogen in the reactivity series and thus it is unreactive towards acids. We can understand from the above discussion that gold metal does not react with acids.
Toughness, however, refers to a mineral's resistance to breaking. Gold is very tough, and will only break along a solder line, a place where the width is very thin, or a defective area of pitting (tiny air bubbles from a poor quality fabrication).
Chlorine (and bromine, also sometimes used in pools) as well as some other common household chemicals, such as bleaches, deep cleaners, detergents, solvents, etc., can and will affect karat gold causing a condition called stress corrosion.
Nitric acid can remove gold atoms from the submerged piece of gold in it, but equilibrium is established quickly and those dissolved gold atoms again get back to the surface of the gold piece. Even concentrated nitric acid cannot dissolve gold, equilibrium will inevitably establish in it.
WHY BLEACH & CHLORINE DAMAGES GOLD. metals—eventually converting them into a type of salt making your gold and prongs brittle and permanently damaging the crystal structure!