A symplectite is a specific mineral intergrowth formed when a single, high-temperature mineral phase becomes unstable and breaks down into two distinct, interwoven minerals. The resulting structure is incredibly fine-grained, often requiring a microscope to identify. Petrologists analyze symplectites to trace the cooling paths and tectonic uplift history of metamorphic and igneous rocks.
The garnet crystals are surrounded by a plagioclase-pyroxene symplectite, indicating rapid decompression of the host rock.
Related terms
Symplectic
Describes a rock texture featuring an intimate, worm-like intergrowth of two different minerals.
Granophyric
An igneous rock texture characterized by the microscopic intergrowth of quartz and feldspar.
Petrography
The detailed scientific description and classification of rocks based on their mineral content and texture.