Potassic-richterite is a rare member of the amphibole supergroup, characterized by potassium dominance in the A-site of the crystal structure. It often forms slender, prismatic, or acicular crystals and is most notably found in alkaline intrusive complexes and contact-metamorphosed skarns.
Is this potassic-richterite?
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-richterite with a known reference. Potassic-richterite 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-richterite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Potassic-richterite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: brown, yellow-brown, green, dark brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic crystals, fibrous, acicular.
Often confused with
Potassic-richterite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside potassic-richterite
Minerals reported to co-occur with potassic-richterite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- KNaCaMg₅Si₈O₂₂(OH)₂
- Mohs hardness
- 5-6
- Density
- 3.0-3.1 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic Crystals, Fibrous, Acicular
- Cleavage
- Perfect Prismatic
- Rarity
- Rare
- Uses
- Collector, Study
- Host rock
- Alkaline Igneous Rocks, Contact Metamorphosed Limestones
- Typical price
- $20-150 per specimen depending on crystal quality
Where rockhounds find potassic-richterite
Classic worldwide localities
- Mont Saint-Hilaire, Canada
- Khibiny Massif, Russia
- Jacupiranga, Brazil
- Ladakh, India
Field-hunting tip
Look in alkaline igneous rocks, contact metamorphosed limestones country — that is the host setting where potassic-richterite typically forms. If you start seeing calcite, diopside, apatite in float, you are in the right ground. Field specimens usually show a prismatic crystals, fibrous, acicular habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify potassic-richterite?+
Where is potassic-richterite found?+
How much is potassic-richterite worth?+
What rocks look like potassic-richterite?+
What minerals are found with potassic-richterite?+
What kind of rock does potassic-richterite form in?+
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Find potassic-richterite on the map
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