metamorphic

Greenstone

Metabasalt / Metavolcanic rock

AI-generated identification · may be incorrect

Hardness: 5-6 on the Mohs scale, Color: Greenish-gray to dark green due to chlorite and epidote, Luster: Dull to sub-vitreous, Crystal structure: Microcrystalline to fine-grained, Cleavage: None distinct, Specific Gravity: 2.8-3.0

Identified July 30, 2026More metamorphic →

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Physical properties

Formation & geological history

Formed through low-grade regional metamorphism of mafic volcanic rocks such as basalt, diabase, or gabbro, typically in ancient submarine environments or orogenic belts.

Uses & applications

Used historically for stone axes and weapons, landscaping, decorative stone, and occasionally as a low-grade aggregate in construction.

Geological facts

Greenstone is frequently associated with ancient shield areas and is notable for its durability and toughness, which made it a favored material for indigenous toolmaking.

Field identification & locations

Identified by its distinctive greenish hue and fine-grained texture. Commonly found in ancient greenstone belts around the world, such as the Canadian Shield and parts of Western Australia.