Gold
Metallic gold is non-toxic, which is unusual for a heavy metal. Soluble gold compounds, however, are toxic to the liver and kidneys. Gold is non-flammable, even in a pure oxygen environment or when finely powdered. It does not react with most household or laboratory chemicals. Gold is commonly processed with cyanide, which is highly toxic.  Most of the cyanide is destroyed in the production process, so it is not present in the final product, but it can be a hazard to workers in a gold processing plant. Since gold conducts electricity, gold jewelry should never be worn when working with electricity.