Former executive chairman Bob Wilde will stay on as chairman but relinquishes his executive role.
Majestic is painting Wilde's step backwards and Mostert's inclusion as a positive for the company given its planned growth path.
Neither Wilde or Mostert were available for comment but in a short statement to the ASX Wilde said Mostert's appointment ended an eight-month search for an executive CEO.
"Majestic is now at the stage in the mining industry where the company needed to expand its management team as it is now operating two diamond mines," Wilde said.
"Charles' appointment is complementary to the existing management structure."
Most recently Mostert had been employed by Majestic as a consultant. He was also an active player in Majestic's attempted takeover of Namakwa Diamonds.
MiningNews.net understands Mostert was approached to head the company this morning after filing an operational review of Majestic for dissemination at a recent board meeting.