Marmolite is a foliated or platy variety of serpentine that exhibits a distinct pearly luster. Collectors look for its characteristic leaf-like or layered structure, which distinguishes it from massive serpentinite, typically occurring as thin sheets within veins.
Is this marmolite?
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 marmolite with a known reference. Marmolite sits at Mohs 2.5-3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: pearly.
- 4Match the color rangeCompare against the expected color range: green, pale green, white.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: platy, foliated, or lamellar.
Often confused with
Marmolite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside marmolite
Minerals reported to co-occur with marmolite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Mg₃Si₂O₅(OH)₄
- Mohs hardness
- 2.5-3
- Density
- 2.5-2.6 g/cm³
- Colors
- Streak
- White
- Luster
- Pearly
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Platy, foliated, or lamellar
- Cleavage
- Perfect basal
- Rarity
- Common
- Uses
- Collector, Lapidary
- Host rock
- ultramafic rocks altered by hydrothermal fluids
Where rockhounds find marmolite
1 mapped spotsClassic worldwide localities
- Hoboken, New Jersey, USA
- Lancaster County, Pennsylvania, USA
- Val di Susa, Italy
Field-hunting tip
Where it forms: ultramafic rocks altered by hydrothermal fluids. If you start seeing chrysotile, antigorite, calcite in float, you are in the right ground. Typical habit: platy, foliated, or lamellar. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in North Carolina. Start trip planning there.
More marmolite photos
Common questions
How do you identify marmolite?+
Where is marmolite found?+
Can I find marmolite in the United States?+
What rocks look like marmolite?+
What minerals are found with marmolite?+
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Find marmolite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
