The 36-year-old is the general manager of Foradex, which owns 23% of Stellar.
Peter Daresbury, chairman of the West Africa focused explorer, said: "We are delighted to welcome Liviu to the board of Stellar.
“Foradex Invest is a significant shareholder of Stellar and Liviu's presence on the board will further consolidate this support.
“The board looks forward to working closely with Liviu and Foradex as Stellar pursues its strategy of developing significant kimberlite diamond resources in Guinea and Sierra Leone in to production.
“On behalf of the board I would also like to thank James Campbell for his dedicated service and support over the years and wish him every success in his future endeavours."