In 1850, coins were introduced in denominations of 1 Centime, 2 Centimes, 5 Centimes, 10 Centimes 20 Centimes, franc, 1 franc, 2 francs and 5 francs. The 1 Centime and 2 Centimes coins were struck in bronze, the 5 Centimes, 10 Centimes and 20 Centimes in billon (with 5% to 15% silver content), and the franc, 1 franc, 2 francs and 5 francs in .900 fine silver. Between 1860 and 1863, .800 fine silver was used, before the standard used in France of .835 fineness was adopted for all silver coins except the 5 francs (which remained .900 fineness) in 1875. In 1879, billon was replaced by cupronickel in the 5 Centimes and 10 Centimes coins and by nickel in the 20 Centimes piece. Gold coins in denominations of 10, 20, and 100 francs, known as Vreneli, circulated until 1936.