Lepidolite is a lithium-rich mica known for its distinctive lilac to purple color and scaly, foliated habit. It is found primarily in granite pegmatites and is an important secondary ore for lithium production. Collectors prize it for its glittering appearance and association with other rare pegmatite minerals like colorful tourmalines.
Is this lepidolite?
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 lepidolite with a known reference. Lepidolite sits at Mohs 2.5-4, 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 to vitreous.
- 4Match the color rangeCompare against the expected color range: lilac, pink, violet, purple, white, grayish, colorless, gray white, yellowish.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: foliated, massive, platy.
Often confused with
Lepidolite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads pearly to vitreous on Lepidolite and vitreous to pearly or silky on Muscovite.
How to tell apart: Luster reads pearly to vitreous on Lepidolite and vitreous, pearly on cleavage on Zinnwaldite.
Often found alongside lepidolite
Minerals reported to co-occur with lepidolite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- KLi₂Al(Al,Si)₃O₁₀(F,OH)₂
- Mohs hardness
- 2.5-4
- Density
- 2.8-2.9 g/cm³
- Streak
- White
- Luster
- Pearly to vitreous
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
- Crystal habit
- Foliated, massive, platy
- Cleavage
- {001}, perfect
- Rarity
- Common
- Uses
- Collector, Lithium ore, Ornamental
- Host rock
- In granite pegmatites, derived by metasomatic replacement of muscovite or biotite; in some high-temperature quartz veins, greisens, and granites
Where rockhounds find lepidolite
17 mapped spotsClassic worldwide localities
- Mt. Mica, near Paris, Oxford Co., and Auburn, Androscoggin Co., Maine, USA
- Mesa Grande and Pala districts, San Diego Co., California, USA
- Brown Derby pegmatite, Gunnison Co., Colorado, USA
- Ingersoll mine, near Keystone, Pennington Co., South Dakota, USA
- Rožná, near Bystřice, Czech Republic
- Alabashka, Ural Mountains, Russia
Field-hunting tip
Where it forms: In granite pegmatites, derived by metasomatic replacement of muscovite or biotite; in some high-temperature quartz veins, greisens, and granites. If you start seeing spodumene, elbaite, amblygonite in float, you are in the right ground. Typical habit: foliated, massive, platy. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in California, Maine, North Carolina. Start trip planning there.
Common questions
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Find lepidolite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
