Gold (Au), symbolised from the latin word Aurum, meaning shining dawn, is a soft malleable metal with excellent conductive properties, lending its use to computer circuit board contacts and wiring. Gold is one of only a handful of elements found only in its raw state, as it is very unreactive. The purity of gold is measured in karats, with 24 being 100% pure, 12 being 50%, etc. The word gold is of German origin, translating roughly to glow.

Although gold is readily available for purchase as jewellery, it can be extracted from other items that make use of it. Old circuit boards can be purchased relatively cheap from computer repair shops. the “fingers”, or connector for the circuit board, usually uses gold plating. For every 100g of fingers, you can get about 1g of gold.

Begin by chopping the fingers off the circuit boards. Plave them into a large glass jar and pour in hydrochloric acid to cover it. Add about 150mL of hydrogen peroxide and stir with a glass stick. A visible reaction will begin immediately, so keep it covered with a glass plate. After a few minutes, add another 150mL of hydrogen peroxide and stir again. After another few minutes, add a final 300mL of peroxide and stir. Cover and leave for about 18 hours, stirring occasionally. By the end, most of the gold plates should have separated off the boards, and the liquid will be black. Using an air pump to bubble the solution will aid this process.

Use a kitchen strainer and pour everything through to filter out the circuit boards. Rinse it with water to capture any clinging gold plates. Now pass the peroxide-acid solution with the gold through a coffee filter, rinsing and filtering all the gold out of ev everything with water. Give the collected gold a final rinse in the filter with hydrochloric acid.

Put the gold, filter and all, into a clean glass beaker and cover with fresh hydrochloric acid. Add about 15mL of household bleach (sodium hypochlorite). Gradually add additional bleach while stirring until you acheive a 2:1 ratio of acid to bleach. The gold should be fully dissolved in about 20-40 minutes, becoming gold (auric) chloride (AuCl₃).

Filter the now yellow solution through a coffee filter, rincing with water until it filters through colourless. Add some sodium metabisulphite to the solution and stir. The gold should quickly precipitate out and sink to the bottom and a brownish-red powder. After 20 minutes, decant the liquid.

The powder can now be heated to 1065 °C / 1950 °F to melt it into solid gold metal. be sure to use some borax in the heating crucible to prevent the gold from sticking. Once it has melted, allow it to solidify before dropping it in water, before the molten borax cools.

There is a video of this process available on YouTube.