Ferri-pedrizite is a rare sodium-lithium rich amphibole typically found in specialized pegmatitic environments. Collectors often identify it by its dark, prismatic habit, though positive identification usually requires chemical analysis due to its similarity to other members of the amphibole group.
Is this ferri-pedrizite?
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 ferri-pedrizite with a known reference. Ferri-pedrizite 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. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: black, dark brown, dark green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: prismatic crystals.
Often confused with
Ferri-pedrizite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Ferri-pedrizite leaves white, Arfvedsonite leaves deep bluish gray, gray-green.
How to tell apart: Streak differs, so Ferri-pedrizite leaves white, Riebeckite leaves greenish brown.
How to tell apart: Streak differs, so Ferri-pedrizite leaves white, Glaucophane leaves blue-gray.
Often found alongside ferri-pedrizite
Minerals reported to co-occur with ferri-pedrizite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- NaLi₂[Fe₂Mg₂Li]Si₈O₂₂(OH)₂
- Mohs hardness
- 5-6
- Density
- 3.1-3.3 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Prismatic crystals
- Cleavage
- Perfect on {110}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- granite pegmatites
Where rockhounds find ferri-pedrizite
Classic worldwide localities
- Pedriza Massif, Spain
- Siberia, Russia
- Quebec, Canada
Field-hunting tip
Where it forms: granite pegmatites. If you start seeing quartz, albite, microcline in float, you are in the right ground. Typical habit: prismatic crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify ferri-pedrizite?+
Where is ferri-pedrizite found?+
What rocks look like ferri-pedrizite?+
What minerals are found with ferri-pedrizite?+
What kind of rock does ferri-pedrizite form in?+
What is ferri-pedrizite used for?+
Find ferri-pedrizite on the map
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