In igneous petrology, a phenotype is an aphanitic igneous rock which is identified and classified according to the mineralogy of its phenocrysts, when it is impossible to determine the mineralogy of the groundmass. [1] Because phenocrysts represent the earlier part of crystallisation, and a melt may have evolved somewhat in between stages of cooling, they cannot be used to accurately describe the rock's true mineralogy or chemistry, but do provide an approximate estimation. As a result of this potential for error, phenotypes are identified using the prefix pheno-. [1]
References
.jpg){kind=small} | This article about igneous petrology is a stub. You can help Wikipedia by expanding it. |