Primocryst

A primocryst is a reference to the earliest-formed crystals, in contact with each other in a magma. These may also be referred to as cumulus crystals.[1]

References

1. Terminology of postcumulus processes and products in the Rhum layered intrusion: Terminology of postcumulus processes and products in the Rhum layered intrusion, accessdate: March 10, 2017