metamorphic
Quartz–mica-rich metamorphic rock (likely mica schist)
Quartz–muscovite ± biotite schist; exact identification requires examination of a fresh surface
AI-generated identification · may be incorrectPale cream to gray, coarse and visibly foliated, with reflective mica flakes and quartz-rich patches. Quartz has Mohs hardness 7; muscovite 2–2.5 and biotite 2.5–3; the specimen’s grain size and cleavage are not fully clear from the photo.
Identified More metamorphic →
Explore Quartz–mica-rich metamorphic rock (likely mica schist) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Pale cream to gray, coarse and visibly foliated, with reflective mica flakes and quartz-rich patches. Quartz has Mohs hardness 7; muscovite 2–2.5 and biotite 2.5–3; the specimen’s grain size and cleavage are not fully clear from the photo.
Formation & geological history
Likely formed when clay-rich sediment or an older felsic rock was buried, heated, and compressed, aligning mica minerals into foliation. Its age cannot be determined from appearance; metamorphic rocks occur in the regional Arabian–Nubian Shield.
Uses & applications
Schist is used locally as building or decorative stone and is mainly of interest to collectors; this rough piece does not appear gem-grade.
Geological facts
The glittering flakes are likely mica, while the pale, harder-looking material is likely quartz or feldspar. Mica splits into thin sheets; quartz does not.
Field identification & locations
The reported coordinates are in northeastern Somalia, where crystalline basement rocks of the Arabian–Nubian Shield make metamorphic rocks plausible. Look for parallel, shiny mica layers and test whether pale grains scratch glass; a geologist should check a fresh break to distinguish schist from weathered quartz–feldspar rock.
More like this
