How can you identify Hornfels?

Compare several properties rather than relying on colour alone. This entry records rock type: Metamorphic Contact; texture: Hornfelsic fine, equigranular, massive; grain size: Fine; common minerals: Andalusite, Cordierite, Biotite, Quartz, Feldspar. Confirm an important identification with additional field tests or qualified laboratory work.

What is Hornfels commonly confused with?

Hornfels may be confused with Basalt, Chert, Quartzite. Compare multiple diagnostic properties because colour and surface appearance can overlap.

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Hornfels identification and geology

Hard, fine-grained, non-foliated metamorphic rock formed by contact metamorphism adjacent to igneous intrusions. Texture: Hornfelsic fine, equigranular, massive. Rock type: Metamorphic Contact. Grain size: Fine. Parent rock: Shale/Mudstone/Sandstone. Minerals present: Andalusite, Cordierite, Biotite, Quartz, Feldspar. Formation: Forms in the contact metamorphic aureole surrounding igneous intrusions, baked by heat without directed pressure. Common geological settings: Found surrounding igneous intrusions worldwide; aureole width depends on intrusion size. Common look-alikes and related entries: Basalt, Chert, Quartzite.

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Basalt

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: 2026-03-30T14:38:47.509954+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 Hornfels?: Hard, fine-grained, non-foliated metamorphic rock formed by contact metamorphism adjacent to igneous intrusions.
How can you identify Hornfels?: Compare several properties rather than relying on colour alone. This entry records rock type: Metamorphic Contact; texture: Hornfelsic fine, equigranular, massive; grain size: Fine; common minerals: Andalusite, Cordierite, Biotite, Quartz, Feldspar. Confirm an important identification with additional field tests or qualified laboratory work.
How does Hornfels form?: Forms in the contact metamorphic aureole surrounding igneous intrusions, baked by heat without directed pressure.
Where is Hornfels commonly found?: Found surrounding igneous intrusions worldwide; aureole width depends on intrusion size.
What is Hornfels commonly confused with?: Hornfels may be confused with Basalt, Chert, Quartzite. Compare multiple diagnostic properties because colour and surface appearance can overlap.

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Hornfels identification and geology

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Sources, scope & corrections

Common questions