Triphylite is a phosphate mineral primarily found in lithium-rich granite pegmatites. It is often identified by its characteristic blue-green to grayish-blue color, though it readily alters to dark brown or black manganese-iron oxides when exposed to air.
Is this triphylite?
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 triphylite with a known reference. Triphylite sits at Mohs 4-4.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Triphylite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Triphylite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: blue, blue-green, grayish-blue, brown.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: short prismatic crystals, massive, granular.
Often confused with
Triphylite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside triphylite
Minerals reported to co-occur with triphylite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- LiFePO₄
- Mohs hardness
- 4-4.5
- Density
- 3.5 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Short Prismatic Crystals, Massive, Granular
- Cleavage
- Perfect On {001}, Good On {010}
- Rarity
- Uncommon
- Uses
- Collector, Scientific Research
- Host rock
- Granite Pegmatites
- Typical price
- $20-150 for thumbnail to small cabinet specimens
Where rockhounds find triphylite
1 mapped spotsClassic worldwide localities
- Hagendorf, Germany
- Keystone, South Dakota, USA
- Newry, Maine, USA
- Norrö, Sweden
- Brazil
Field-hunting tip
Look in granite pegmatites country — that is the host setting where triphylite typically forms. If you start seeing quartz, albite, beryl in float, you are in the right ground. Field specimens usually show a short prismatic crystals, massive, granular habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Wisconsin — start trip planning there.
Common questions
How do you identify triphylite?+
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Can I find triphylite in the United States?+
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Find triphylite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
