Potassic-chloro-pargasite is a rare member of the amphibole supergroup characterized by its potassium and chlorine content. It typically forms in high-grade metamorphic environments and skarns, often occurring as dark, opaque to translucent prismatic crystals.
Is this potassic-chloro-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-chloro-pargasite with a known reference. Potassic-chloro-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-chloro-pargasite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Potassic-chloro-pargasite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: black, dark brown, dark green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic crystals, anhedral grains.
Often confused with
Potassic-chloro-pargasite vs. its common look-alikes — and how to tell them apart in the field.


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

How to tell apart: Streak differs — Potassic-chloro-pargasite leaves white, Hastingsite leaves white to light gray.
Often found alongside potassic-chloro-pargasite
Minerals reported to co-occur with potassic-chloro-pargasite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- NaCa₂Mg₄Al(Si₆Al₂)O₂₂Cl₂
- Mohs hardness
- 5-6
- Density
- 3.1-3.2 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic Crystals, Anhedral Grains
- Cleavage
- Perfect On {110}
- Rarity
- Rare
- Uses
- Collector, Scientific Research
- Host rock
- Metamorphic Rocks, Skarns, Marble
- Typical price
- $20-150 per specimen
Where rockhounds find potassic-chloro-pargasite
Classic worldwide localities
- Ladoga region, Russia
- Kola Peninsula, Russia
- Grenville Province, Canada
Field-hunting tip
Look in metamorphic rocks, skarns, marble country — that is the host setting where potassic-chloro-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, anhedral grains habit, so train your eye for that shape before scanning the outcrop.




