In Geneva and in the neighboring regions great virtues are ascribed to a cut and facetted iron (pyrite), very hard, susceptible of a high polish and of resplendent lustre. This is cut to resemble the rose or brilliant form of diamond, and is set in rings, buckles, and other ornaments. In appearance it resembles polished steel and is called _pierre de santé_, or “health-stone,” for it is believed to grow pale when the health of the wearer is about to fail.[309] This substance is known as marcasite and is a bisulphide of iron. In the time of Louis XVI it was largely used for ornamental purposes; at present steel has almost entirely taken its place, although it is still utilized to a limited extent. Many believe that this is the material to which Victor Hugo alludes in his great romance, “Les Miserables,” as having been manufactured by Jean Valjean. Rock-crystal Medical men in Rome, in the first century, attested that no better cautery for the human body could be used than a crystal ball acted upon by the sun’s rays,[310] and this use of the material seems to have been very general at that time. In his commentary on Andrea Bacci’s gem-treatise, Wolfgang Gabelchover, the German translator, says that a German name of rock-crystal in his time, the early sixteenth century, was _Schwindelstein_ (“vertigo-stone”), because it was believed to preserve the wearer from attacks of dizziness. Other remedial or physical effects of rock-crystal are also noted. Taken as a powder in dry wine, it was a cure for dysentery, and the physician, Christopher Barzizius, taught that if its powder were mixed with honey and administered to mothers, they would be the better able to nurse their offspring.[311] The following lines by Robert Wilson (d. 1600), a popular sixteenth-century comedy writer, credit amber and rock-crystal with qualities not commonly ascribed to them, although the fancied growth of rock-crystal from a piece of ice probably explains its supposed styptic virtue:[312] LUCRE: And if they demand wherefore your wares and merchandise agree, You must say, jet will take up a straw; amber will make one fat; Coral will look pale when you be sick, and crystal stanch blood.