Anthophyllite is a magnesium-rich amphibole typically found in regionally metamorphosed rocks. It is easily identified by its characteristic clove-brown to grayish color and its fibrous or lamellar habit, though it should be handled with extreme caution due to its asbestiform nature.
Is this anthophyllite?
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 anthophyllite with a known reference. Anthophyllite sits at Mohs 5.5-6, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white or grayish.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous, pearly on cleavage.
- 4Match the color rangeCompare against the expected color range: brown, gray, white, greenish, greenish gray, green, clove brown, brownish green.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: fibrous, lamellar, massive.
Often confused with
Anthophyllite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside anthophyllite
Minerals reported to co-occur with anthophyllite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Mg₂Mg₅Si₈O₂₂(OH)₂
- Mohs hardness
- 5.5-6
- Density
- 3.09 g/cm³
- Colors
- Streak
- White or grayish
- Luster
- Vitreous, pearly on cleavage
- Transparency
- Transparent to translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Fibrous, lamellar, massive
- Cleavage
- Perfect on {210}, intersecting at 54.5° and 125.5°; distinct on {010} and {100}
- Fluorescence
- Red under SW and LW UV
- Rarity
- Common
- Uses
- Collector, Geological study
- Host rock
- From medium- or high-grade metamorphism, in amphibolites, gneisses, metaquartzites, iron formations, granulites, and schists derived from argillaceous sediments, ultramafic, or mafic igneous rocks
Where rockhounds find anthophyllite
2 mapped spotsClassic worldwide localities
- Chesterfield, Hampshire Co., Massachusetts, USA
- Carleton talc mine, near Chester, Windsor Co., Vermont, USA
- Media, Delaware Co., Pennsylvania, USA
- Day Book deposit, near Spruce Pine, Mitchell Co., North Carolina, USA
- Kongsberg and Snarum, Norway
- Schneeberg, Saxony, Germany
Field-hunting tip
Where it forms: From medium- or high-grade metamorphism, in amphibolites, gneisses, metaquartzites, iron formations, granulites, and schists derived from argillaceous sediments, ultramafic, or mafic igneous rocks. If you start seeing cordierite, talc, chlorite in float, you are in the right ground. Typical habit: fibrous, lamellar, massive. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in California, New York. Start trip planning there.
Common questions
How do you identify anthophyllite?+
Where is anthophyllite found?+
Can I find anthophyllite in the United States?+
Is anthophyllite safe to handle?+
What rocks look like anthophyllite?+
What minerals are found with anthophyllite?+
What kind of rock does anthophyllite form in?+
What is anthophyllite used for?+
Find anthophyllite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
