metamorphic
Weathered schist or gneiss boulder
Micaceous quartz-feldspar schist/gneiss; exact identification is limited by the photograph
AI-generated identification · may be incorrectHardness about 5–7 Mohs; mottled gray, tan, pink, and green surface with a dull to slightly sparkly luster. The apparent foliation and fractures suggest aligned mica and recrystallized quartz-feldspar; cleavage is mainly along micaceous layers.
Identified More metamorphic →
Explore Weathered schist or gneiss boulder in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness about 5–7 Mohs; mottled gray, tan, pink, and green surface with a dull to slightly sparkly luster. The apparent foliation and fractures suggest aligned mica and recrystallized quartz-feldspar; cleavage is mainly along micaceous layers.
Formation & geological history
Formed when preexisting sedimentary or igneous rock was buried and subjected to elevated heat and pressure, commonly during mountain building. Its age cannot be determined visually and may range from Precambrian to younger depending on locality.
Uses & applications
Used locally as landscape stone, retaining-wall material, and construction aggregate; attractive pieces may be polished or displayed as specimens.
Geological facts
The rusty colors reflect oxidation of iron-bearing minerals, while green areas may represent chlorite or epidote. Weathering can obscure the original foliation and make schist resemble altered granite.
Field identification & locations
Look for planar layering, mica sparkle, quartz-rich bands, and a tendency to split along foliation; a streak, acid, and hardness test would improve identification. Common in exposed mountain belts and glacial deposits.
More like this
