100 Baisa - Qaboos Coinage

Oman introduced bimetallic coinage in 1991 as part of a broader modernization of its circulating series under the Central Bank, which had only been formally established in 1974 — itself a product of Sultan Qaboos's sweeping administrative reforms following the 1970 palace coup that deposed his father Said bin Taimur. The aluminium bronze and copper-nickel combination was chosen for its resistance to the Gulf's corrosive humid climate and to deter counterfeiting of the highest-value circulating coin in the series.

The 100 Baisa denomination represented one-tenth of a Rial Omani, a currency that had replaced the Gulf Rupee only in 1972.