Potassic-ferro-taramite is a rare member of the amphibole supergroup, typically found in high-grade metamorphic complexes. It generally forms dark, prismatic crystals that are difficult to distinguish from other common hornblende-series minerals without sophisticated chemical analysis.
Is this potassic-ferro-taramite?
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 potassic-ferro-taramite with a known reference. Potassic-ferro-taramite sits at Mohs 5-6 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Potassic-ferro-taramite leaves a white to pale grey streak.
- 3Read the lusterHold the specimen under a strong light. Potassic-ferro-taramite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: black, dark green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic crystals.
Often confused with
Potassic-ferro-taramite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside potassic-ferro-taramite
Minerals reported to co-occur with potassic-ferro-taramite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- {K}{Na}{Ca}{Fe²⁺₃Mg₂}{Al₂Si₆O₂₂}(OH)₂
- Mohs hardness
- 5-6
- Density
- 3.3-3.5 g/cm³
- Colors
- Streak
- White to Pale Grey
- Luster
- Vitreous
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic Crystals
- Cleavage
- Perfect On {110}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Metamorphic Rocks
- Typical price
- $20-100 per specimen
Where rockhounds find potassic-ferro-taramite
Classic worldwide localities
- Ukraine
- Finland
- Russia
Field-hunting tip
Look in metamorphic rocks country — that is the host setting where potassic-ferro-taramite typically forms. If you start seeing plagioclase, quartz, biotite in float, you are in the right ground. Field specimens usually show a prismatic crystals habit, so train your eye for that shape before scanning the outcrop.





