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.

Hardness
5-6
Mohs
Luster
Vitreous
Streak
White
Transparency
Translucent

Is this potassic-ferro-pargasite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

  • 1
    Test the hardness
    Try 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.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Potassic-ferro-pargasite leaves a white streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Potassic-ferro-pargasite typically shows a vitreous luster.
  • 4
    Match the color range
    Compare against the expected color range: black, dark green, brown.
  • 5
    Look at form & habit
    Crystal 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.

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
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.

Common questions

How do you identify potassic-ferro-pargasite?+
Mohs hardness is 5-6. It typically shows a vitreous luster. The streak is white. Common colors include black, dark green, brown.
Where is potassic-ferro-pargasite found?+
Notable localities include Kola Peninsula, Russia; Franklin, New Jersey, USA; Various metamorphic terrains.
How much is potassic-ferro-pargasite worth?+
Typical asking prices fall in the range of $20-150 for mineral specimens. Quality, size, and provenance can move individual specimens well outside that range.
What rocks look like potassic-ferro-pargasite?+
Potassic-ferro-pargasite is most often confused with Hornblende, Pargasite, Ferro-pargasite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with potassic-ferro-pargasite?+
Potassic-ferro-pargasite commonly co-occurs with Calcite, Diopside, Phlogopite, Titanite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does potassic-ferro-pargasite form in?+
Potassic-ferro-pargasite typically forms in metamorphic rocks like skarns and amphibolites. Working float back to the host body is the standard way to chase a fresh occurrence.
What is potassic-ferro-pargasite used for?+
Potassic-ferro-pargasite is used in collector, scientific research.

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