The earliest formed crystals (phenocrysts) in a magma tend to be _________.
A) crowded and irregular in shape
B) larger and well formed because they have space to grow and a ready supply of ions
C) small and clouded with inclusions of everything that formed later on
D) those that can form only at the lowest temperatures

Question

Quizplus · Accepted Answer

Phenocrysts are the earliest formed crystals in a magma and tend to be larger and well-formed because they have more space to grow and a readily available supply of ions. This allows them to develop clear, distinct shapes before the magma becomes too crowded with other crystals.

The Earliest Formed Crystals (Phenocrysts) in a Magma Tend to Be