A gold refining kit consists of various chemicals that are used for refining and purifying gold. These chemicals are: Nitric Acid, Hydrochloric Acid, Urea and Sodium Meta Bisulphite. A commonly used professional and safe kit for refining gold is The Simplicity Gold and Platinum System. According to Instructables.com, the substances in these kits are highly dangerous, because they put users at risk for inhaling hazardous materials.
The DIY kits consists of a set of chemicals for refining gold are widely available through various online outlets. A kit like this, such as the one sold by Shor International, can be found on Amazon for the price of $87, as of 2014.
Another option for gold refining, however, is The Simplicity Gold Refining System, which comes at an extra price for some additional safety precautions. This system consists of the Simplicity appliance, GC Salt, Precipitant and Catalyst. It refines gold by dissolving it inside of the appliance in a special salt water bath, a powder added to the water that transforms the gold into solid particles and leaves the other metals in liquid form. The pure gold particles remain at the bottom of the container, and then the rest of the liquid is poured away.