TRIPOLI

Dictionary of Science, Literature and Art · 1842 · p. 47

A mineral used for polishing, originally from Tripoli in Barbary. It occurs in friable earthy ma es of a dull clay colour. Its e ential components are silica, alumina, and oxide of iron; but the varieties of tripoli appear to vary extremely in composition. Ehrenberg has found the different tripolis to be aggregates of silicified animalcules. [s. 1276]