Stephanite has been the subject of two important memoirs. Schröder examined minutely the crystals from Andreasbcrg ; Vrba has described fully the character of the stephanite from Przibram and other localities, and has given at the same time a summary of the observations of previous mineralogists, so that his memoir constitutes a monograph of the mineral.

By neither of these observers, however, nor elsewhere, has it been stated that stephanite is hemimorphic, although it has been suspected of being possibly hemihedral.

It is the object of the present paper to establish the hemimorphism of stephanite upon evidence similar to that which has been employed in the case of pyrargyrite.