Ferro-ferri-pedrizite is a very rare member of the amphibole group defined by its specific lithium and iron content. It typically forms as small, elongated prisms within evolved granite pegmatites and is primarily of interest to advanced mineralogists and systematic collectors.

Hardness
5-6
Mohs
Luster
Vitreous
Streak
White
Transparency
Translucent

Is this ferro-ferri-pedrizite?

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 ferro-ferri-pedrizite with a known reference. Ferro-ferri-pedrizite 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. Streak: white.
  • 3
    Read the luster
    Hold the specimen under a strong light. Luster: vitreous.
  • 4
    Match the color range
    Compare against the expected color range: pale yellow, pale green.
  • 5
    Look at form & habit
    Crystal system: monoclinic. Typical habit: prismatic crystals.

Often confused with

Ferro-ferri-pedrizite vs. its common look-alikes, and how to tell them apart in the field.

Often found alongside ferro-ferri-pedrizite

Minerals reported to co-occur with ferro-ferri-pedrizite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula
NaLi₂(LiFe₂Fe₂)Si₈O₂₂(OH)₂
Mohs hardness
5-6
Density
3.16 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 ferro-ferri-pedrizite

Classic worldwide localities

  • Pedriza Massif, Spain

Field-hunting tip

Where it forms: granite pegmatites. If you start seeing albite, quartz, k-feldspar 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 ferro-ferri-pedrizite?+
Mohs hardness is 5-6. Luster: vitreous. The streak is white. Common colors include pale yellow, pale green.
Where is ferro-ferri-pedrizite found?+
Notable localities include Pedriza Massif, Spain.
What rocks look like ferro-ferri-pedrizite?+
Ferro-ferri-pedrizite is most often confused with Arfvedsonite, Ferri-leakeite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with ferro-ferri-pedrizite?+
Ferro-ferri-pedrizite commonly co-occurs with Albite, Quartz, K-feldspar, Aegirine. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does ferro-ferri-pedrizite form in?+
Where it forms: granite pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.
What is ferro-ferri-pedrizite used for?+
Ferro-ferri-pedrizite is used in collector.

Find ferro-ferri-pedrizite on the map

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