metamorphic

Likely blue-gray slate

Slate, a fine-grained metamorphic rock composed mainly of mica-group minerals and quartz

AI-generated identification · may be incorrect

Dark blue-gray, dull to slightly satiny, fine-grained and apparently slabby; slate is typically Mohs 3–4 with strong planar cleavage. The image does not show enough detail to confirm its mineral composition or exact identification.

Identified September 23, 2026More metamorphic →

Explore Likely blue-gray slate in the encyclopedia →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Forms when shale or mudstone is subjected to low-grade regional metamorphism, developing slaty cleavage; its age depends on the source rocks and cannot be determined from the image.

Uses & applications

Used for roofing, flooring, paving, and decorative stone; suitable pieces are also collected as specimens.

Geological facts

Slate splits into thin sheets along cleavage planes, unlike many unaltered sedimentary rocks.

Field identification & locations

Look for a very fine texture and flat splitting surfaces; common slate regions include Wales, Vermont, and parts of Spain. The pictured piece could also be another dark, fine-grained rock, so a fresh surface would help identify it.