Everything I said was noted in the original source (including getting money from his dad, his own claims of being extremely wealthy, etc) but Elon's subsequent tweet offering money for evidence and his dad replying to confirm that he owned one was great hilarity that I first saw on Reddit directly linking to Twitter.

Here's a good breakdown, including interview with Errol describing the mine: https://www.thedailybeast.com/elon-musks-dad-errol-shares-deadly-secrets-of-the-fabled-emerald-mine-in-zambia

This might have been his first interview calling out Elon on the tweet: https://www.the-sun.com/news/7911051/elon-musks-dad-errol-emerald-business/