THE 'HMS EREBUS' GOLD CROWN COIN. Denomination - One CROWN. Year Of Issue - 2018. Diameter - 38.6mm. Weight - 25grams. Finish - Fully-Layered with Pure 24-Carat Gold. Quality - Proof. Edge - Milled. Issuing Authority - Tristan Da Cunha. Limited Edition - 19,999 Worldwide.