metamorphic

Likely slate fragment

Slate; predominantly fine-grained mica/clay minerals and quartz

AI-generated identification · may be incorrect

Dark gray-green, dull to slightly silky luster, very fine-grained, with planar cleavage and thin foliation; Mohs hardness about 3–4. The smooth, flat shape suggests a naturally cleaved or manually shaped piece.

Identified September 3, 2026More metamorphic →

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Physical properties

Formation & geological history

Forms when shale or mudstone undergoes low-grade regional metamorphism, typically during mountain building; ages vary from Paleozoic to Precambrian depending on locality.

Uses & applications

Used for roofing, floor and wall tiles, paving, writing tablets, and decorative objects; this small fragment has negligible commercial value.

Geological facts

Slate splits along closely spaced cleavage planes, unlike most sedimentary mudstone. Green coloration may reflect chlorite or other metamorphic minerals.

Field identification & locations

Identify it by thin, even splitting, fine texture, and lack of visible sand grains or large crystals; common in slate belts worldwide, including Wales, Vermont, Spain, and China. A scratch test and locality information would improve confidence.