Introduction to Metallic Antimony

Metallic antimony readily crystallizes. During production, molten antimony is poured into molds. As the liquid antimony cools, a thin coating of easily melt-able material, a couverture, forms on the surface of the cooling metal. This couverture is notable for the fern pattern of crystals that appears on the surface of the solidified antimony. It is said that these crystals sparkle or twinkle like stars. Consequently, the resulting product is called "star antimony". Many people consider the sharpness of the fern pattern to be an indicator of the quality of the material. However, there is no scientific basis for this conclusion as ambient conditions and cooling rate will have a significant impact on crystal size of metallic antimony.