1. A fine-grained igneous rock in which the individual crystals are too small to be seen with the naked eye.
Usage: geology; technical

1. Of or relating to an igneous rock with crystals too small to be distinguished without magnification.
Usage: geology; technical

Examples

• Basalt is a common aphanite formed by rapid cooling of lava at the Earth's surface.
• The aphanite texture indicates that the magma cooled quickly.
• Geologists use microscopes to study the mineral composition of aphanite samples.
• This volcanic rock is classified as an aphanite because its crystals are microscopic.
• The aphanite nature of the specimen suggests it originated from a lava flow rather than a deep intrusion.