Amphibolite identification and geology

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• Gabbro
• Diorite
• Hornblendite

Sources, scope & corrections

These authoritative resources support category-level nomenclature, terminology, identification methods, and safety. When a specimen-specific safety warning appears, the public-health source listed here directly supports that precaution. They are not line-by-line citations for every other property on this entry, and natural specimens vary.

Editorial owner

GeoMiner

Last updated

2026-03-30T14:39:09.496545+00:00

Review status

Published; not independently peer-reviewed

• Rocks — U.S. National Park Service. Authoritative overview of rock groups, the rock cycle, and geologic processes.
• Can you identify my rock or mineral? — U.S. Geological Survey. Identification limitations and routes to in-person professional verification.

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Common questions

What is Amphibolite?

Dark, medium to coarse-grained metamorphic rock composed mainly of hornblende and plagioclase. May be foliated or massive.

How can you identify Amphibolite?

Compare several properties rather than relying on colour alone. This entry records rock type: Metamorphic Foliated to Massive; texture: Nematoblastic to granoblastic; grain size: Medium to coarse; common minerals: Hornblende, Plagioclase, Garnet, Epidote, Quartz. Confirm an important identification with additional field tests or qualified laboratory work.

How does Amphibolite form?

Forms from medium to high grade metamorphism of mafic igneous rocks basalt, gabbro or impure carbonates.

Where is Amphibolite commonly found?

Found in medium-high grade metamorphic terranes worldwide; common in Precambrian shield areas.

What is Amphibolite commonly confused with?

Amphibolite may be confused with Gabbro, Diorite, Hornblendite. Compare multiple diagnostic properties because colour and surface appearance can overlap.