Foliated mica-rich metamorphic rock, likely schist

Medium- to coarse-grained, dark gray-brown rock with a glittery micaceous luster and strong planar foliation; likely Mohs hardness 2–3 on exposed mica surfaces, with variable cleavage and density around 2.7–3.0. The image is insufficient to confirm exact minerals or whether the specimen is polished, coated, or naturally weathered.

Formed when shale or another clay-rich sediment was buried and subjected to elevated heat and directed pressure, recrystallizing into aligned mica; commonly Paleozoic to Precambrian in age depending on locality.

Used locally as decorative stone, landscaping material, and sometimes building facing; attractive mica-rich pieces are collected, though this specimen appears modestly valuable.

The sparkling flakes reflect light from mica cleavage planes, and the layered texture records the direction of metamorphic compression.

Look for easily splitting, parallel layers and abundant reflective mica flakes; confirm with a fresh break, streak, hardness tests, and examination for garnet or quartz. Common in metamorphic belts worldwide, including New England, the Appalachians, Scotland, Scandinavia, and India.