Sphærostilbite was one of a number of sub-species which Beudant in his Mineralogy, published in 1832, separated from ordinary stilblte owing to slight differences in chemical composition. In a typical specimen from the Faroe Islands he describes the sphmrosfilbite as innplanted upon ordinary stilhite, in the form of small globules, presenting a fibrous radiated structure and brilliant pearly lustre on the fractured surface. Unlike stilhite, it gelatinlsed with acids, and it also had a specific gravity (2.31) slightly higher than that of stilhite. According to the analyses given by Beudant, however, it differed in chemical composition so little from ordinary stilbite that in later text-books (Glocker, 1839; Breithaupt, 1847, &c.) it has always been referred to that species.