Augen gneiss is a foliated metamorphic rock characterized by distinct, eye-shaped mineral porphyroclasts, typically of feldspar, embedded in a finer-grained matrix. The name 'augen' comes from the German word for eyes, referring to these large, lenticular crystals stretched by regional metamorphism. Collectors look for high-contrast patterns between the dark foliated bands and the light-colored eye-shaped crystals.
Is this augen gneiss?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch augen gneiss with a known reference. Augen Gneiss sits at Mohs 5-7, softer than the next harder reference, harder than the previous one.
- 2Read the textureLook at a fresh break with a hand lens. Texture: Foliated, with large lens-shaped grains (augen, German for eyes). Grain size: Medium- to coarse-grained.
- 3Pick out the mineralsComposition: Augen commonly of feldspar, quartz or garnet. Identify the two or three most abundant grains.
- 4Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 5Match the color rangeCompare against the expected color range: gray, pink, white, black.
Often confused with
Augen Gneiss vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside augen gneiss
Minerals reported to co-occur with augen gneiss. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Mohs hardness
- 5-7
- Density
- 2.6-2.9 g/cm³
- Luster
- Vitreous
- Transparency
- Opaque
- Rarity
- Common
- Uses
- Decorative, Architectural, Collector
- Host rock
- regional metamorphic terrains
- Texture
- Foliated, with large lens-shaped grains (augen, German for eyes)
- Grain size
- Medium- to coarse-grained
- Composition
- Augen commonly of feldspar, quartz or garnet
Where rockhounds find augen gneiss
Classic worldwide localities
- Norway
- Scotland
- United States
- Canada
- Sweden
Field-hunting tip
Where it forms: regional metamorphic terrains. If you start seeing quartz, feldspar, mica in float, you are in the right ground.
Common questions
How do you identify augen gneiss?+
Where is augen gneiss found?+
What rocks look like augen gneiss?+
What minerals are found with augen gneiss?+
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What is augen gneiss used for?+
Find augen gneiss on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
