From Glossary of Meteorology
(Also called rime splintering.) One of the mechanisms thought to be responsible for secondary ice production, when ice crystal concentrations in clouds well in excess (x 10 000) of the ice nucleus concentration are found.
Ice particles are produced in the range of temperature -3° to -8°C (with a maximum at -4°C) as graupel grows by accretion provided the cloud droplet spectrum contains appropriate numbers of droplets smaller than 12 μm and greater than 25 μm. About 50 splinters are produced per milligram of accreted ice.