There are 13 words that end with 'sium'.
cesium | caesium | hassium |
indusium | dichasium | gymnasium |
magnesium | epimysium | potassium |
symposium | dysprosium | perimysium |
monochasium | ||
Note: These 13 words that end with 'sium' are found from the USA & Canada version of the tournament Scrabble word list.