Potassic-ferro-pargasite is a rare member of the complex amphibole group, characterized by high potassium and iron content. It typically forms dark, prismatic crystals within metamorphic rocks such as skarns. Due to its complex chemistry and limited occurrences, it is primarily a target for advanced mineral collectors.
Is this potassic-ferro-pargasite?
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-pargasite with a known reference. Potassic-ferro-pargasite 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-pargasite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Potassic-ferro-pargasite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: black, dark green, brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic crystals.
Often confused with
Potassic-ferro-pargasite vs. its common look-alikes — and how to tell them apart in the field.

How to tell apart: Streak differs — Potassic-ferro-pargasite leaves white, Hornblende leaves grayish-white.


How to tell apart: Streak differs — Potassic-ferro-pargasite leaves white, Ferro-pargasite leaves white to pale gray.
Often found alongside potassic-ferro-pargasite
Minerals reported to co-occur with potassic-ferro-pargasite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- KCa₂Fe₄Al(Si₆Al₂)O₂₂(OH)₂
- Mohs hardness
- 5-6
- Density
- 3.3-3.5 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic Crystals
- Cleavage
- Perfect Prismatic
- Rarity
- Rare
- Uses
- Collector, Scientific Research
- Host rock
- Metamorphic Rocks Like Skarns and Amphibolites
- Typical price
- $20-150 for mineral specimens
Where rockhounds find potassic-ferro-pargasite
Classic worldwide localities
- Kola Peninsula, Russia
- Franklin, New Jersey, USA
- Various metamorphic terrains
Field-hunting tip
Look in metamorphic rocks like skarns and amphibolites country — that is the host setting where potassic-ferro-pargasite typically forms. If you start seeing calcite, diopside, phlogopite 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.




