'siliceous' originates from Latin, specifically the word 'siliceus', which itself derives from 'silex' (genitive 'silicis'), where 'silex' meant 'flint' or 'hard stone'.

'siliceous' came into English from Late Latin 'siliceus' (meaning 'of flint' or 'made of silex'), passing into scientific and descriptive use in English from the 17th–18th centuries.

Initially it referred to being 'of or made from flint (silex)'; over time it broadened to the current sense 'containing or consisting of silica (silicon dioxide)'.