This has to be Zircon. It has been discovered from Australia and dated back to around 4 billion years, which is probably itself explaining the fact of zircon being one of the most...
Answer: Zircon
Zircon was the oldest mineral found on Earth. It was found from Jack Hills, Australia, where rocks were found to contain the oldest known minerals on Earth
Zircons, the oldest minerals on Earth, preserve robust records of chemical and isotopic characteristics of the rocks in which they form.
Studying oxygen isotopes in the zircons c...