CIPW classification

CIPW classification

[¦sē¦ī¦pē¦dəb·əl·yü ‚klas·ə·fə′kā·shən]
(petrology)
A designation for the Norm system of classifying igneous rocks; from the initial letters of the names of those who devised it: Cross, Iddings, Pirsson, and Washington.