grain

1. Equivalent of crystal in metamorphic rocks. In sedimentary rocks a detrital grain may contain several crystals. 2. The particles or discrete crystals that make up a sediment or rock. 3. The particles which make up settled snow, firn, and glacier ice.

Related terms:

• new grain
• grain size
• grain boundary area reduction
• composite grain
• grain boundary sliding
• left-over grain
• grain shape preferred orientation
• clast
• grain shape fabric
• skeleton grain