Aphanite (2026)

: When lava reaches the Earth's surface or shallow subsurface (hypabyssal environments), it cools too quickly for large crystals to grow.

Aphanites are typically (volcanic) rocks. Their signature microscopic structure is the result of rapid cooling: aphanite

: While the background (matrix) is fine-grained, aphanites frequently contain occasional large crystals called phenocrysts embedded within them. : When lava reaches the Earth's surface or

is a geological term for igneous rocks with a "fine-grained" texture so compact that individual mineral crystals cannot be seen by the naked eye. Derived from the Greek word aphanḗs , meaning "invisible," these rocks appear as a homogeneous, uniform mass without magnification. Formation and Characteristics is a geological term for igneous rocks with

: They are often composed of very small crystals of minerals like plagioclase feldspar, augite, or hornblende.

: Because they form near the surface, they may contain small holes (vesicles) created by escaping gas bubbles during the cooling process. APHANITE Definition & Meaning - Dictionary.com