Gold is a naturally occurring mineral, which means it wasn't invented. It was discovered. There is evidence of the utilization of gold dating back to the Copper Age (approximately 4000 BC).
The evidence of the knowledge and use of gold is ubiquitous, but the first person to find or use it predates history. Many artifacts from ancient civilizations are made of gold, such as Egyptian statues and sarcophagi. Multiple religious texts also reference gold and artifacts made from it, such as the Christian Bible. The process of refining gold goes back to ancient Rome and the invention of hydraulic mining.