Erlianite is a rare phyllosilicate mineral typically found as fibrous or platy brownish aggregates within iron-rich chert formations. It was first identified in China and is highly sought after by systematic mineral collectors due to its restricted locality and complex chemical structure.
Is this erlianite?
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 erlianite with a known reference. Erlianite sits at Mohs 3-4 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Erlianite leaves a yellowish-brown streak.
- 3Read the lusterHold the specimen under a strong light. Erlianite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: brown, yellowish-brown, dark brown.
- 5Look at form & habitCrystal system: trigonal. Typical habit: fibrous, radiated aggregates, platy crystals.
Often confused with
Erlianite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Erlianite leaves yellowish-brown, Stilpnomelane leaves yellowish-brown to greenish-black; luster reads vitreous on Erlianite and pearly on Stilpnomelane.
How to tell apart: Erlianite is noticeably harder (Mohs 3-4 vs. 1-2); streak differs — Erlianite leaves yellowish-brown, Minnesotaite leaves white; luster reads vitreous on Erlianite and pearly on Minnesotaite.
How to tell apart: Streak differs — Erlianite leaves yellowish-brown, Greenalite leaves pale yellow; luster reads vitreous on Erlianite and resinous on Greenalite.
Often found alongside erlianite
Minerals reported to co-occur with erlianite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Fe,Mg,Fe)₄Si₆O₁₅(OH)₂·4H₂O
- Mohs hardness
- 3-4
- Density
- 2.88 g/cm³
- Streak
- Yellowish-brown
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Fibrous, Radiated Aggregates, Platy Crystals
- Cleavage
- Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Iron-rich Sedimentary Chert Formations
- Typical price
- $20-150 thumbnail specimens
Where rockhounds find erlianite
Classic worldwide localities
- Erlianshan, Gansu Province, China
Field-hunting tip
Look in iron-rich sedimentary chert formations country — that is the host setting where erlianite typically forms. If you start seeing quartz, magnetite, hematite in float, you are in the right ground. Field specimens usually show a fibrous, radiated aggregates, platy crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find erlianite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
