A type of precipitation consisting of transparent or translucent pellets of ice, 5 mm or less in diameter. They may be spherical, irregular, or (rarely) conical in shape. Ice pellets usually bounce when hitting hard ground and make a sound upon impact. Now internationally recognized, ice pellets includes two basically different types of precipitation, known in the United States as 1) sleet and 2) small hail. Thus a two-part definition is given: 1) sleet or grains of ice, generally transparent, globular, solid grains of ice that have formed from the freezing of raindrops or the refreezing of largely melted snowflakes when falling through a below-freezing layer of air near the earth's surface; 2) small hail, generally translucent particles, consisting of snow pellets encased in a thin layer of ice. The ice layer may form either by the accretion of droplets upon the snow pellet or by the melting and refreezing of the surface of the snow pellet. Compare hail, graupel.