Here is his father confirming it:

"Errol Musk Claims He Visited Emerald Mine With Son Elon" - https://www.ndtv.com/world-news/after-elon-musks-strong-deni....

"Elon Musk’s dad Errol says he can ‘prove’ existence of emerald mine in new bombshell claim revealing its location" - https://www.the-sun.com/news/7911051/elon-musks-dad-errol-em...