Taneyamalite is a rare manganese-bearing silicate mineral belonging to the ardennite group. It typically occurs as small, delicate, radiating fibrous aggregates within manganese-rich metamorphic environments and is highly sought after by systematic mineral collectors.
Is this taneyamalite?
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 taneyamalite with a known reference. Taneyamalite sits at Mohs 6, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Taneyamalite leaves a yellowish-white streak.
- 3Read the lusterHold the specimen under a strong light. Taneyamalite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellowish-brown, brown, orange-brown.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: fibrous aggregates, radiating needles.
Often found alongside taneyamalite
Minerals reported to co-occur with taneyamalite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Na,Ca)(Mn,Mg,Fe)₁₂Si₁₁AlO₄₄(OH,O)₁₀
- Mohs hardness
- 6
- Density
- 3.55-3.65 g/cm³
- Streak
- Yellowish-white
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Fibrous Aggregates, Radiating Needles
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Manganese-rich Cherts and Metamorphic Rocks
- Typical price
- $50-300 per specimen depending on size and provenance
Where rockhounds find taneyamalite
Classic worldwide localities
- Taneyama mine, Kumamoto Prefecture, Japan
- Cerchiara mine, Liguria, Italy
Field-hunting tip
Look in manganese-rich cherts and metamorphic rocks country, the host setting where taneyamalite typically forms. If you start seeing rhodochrosite, quartz, braunite in float, you are in the right ground. Field specimens usually show a fibrous aggregates, radiating needles habit, so train your eye for that shape before scanning the outcrop.




