Fluorotetraferriphlogopite is a rare mica-group mineral occurring primarily in carbonatites and alkaline igneous environments. Collectors identify it by its characteristic platy, micaceous habit and distinctive iron-rich brown coloration typical of the phlogopite-annite series.
Is this fluorotetraferriphlogopite?
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 fluorotetraferriphlogopite with a known reference. Fluorotetraferriphlogopite sits at Mohs 2.5-3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Fluorotetraferriphlogopite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Fluorotetraferriphlogopite typically shows a pearly luster.
- 4Match the color rangeCompare against the expected color range: brown, yellowish-brown, dark brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: platy crystals, micaceous masses.
Often confused with
Fluorotetraferriphlogopite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside fluorotetraferriphlogopite
Minerals reported to co-occur with fluorotetraferriphlogopite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- KFe²⁺₃(Si₃Fe³⁺)O₁₀F₂
- Mohs hardness
- 2.5-3
- Density
- 2.8-3.0 g/cm³
- Streak
- White
- Luster
- Pearly
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Platy Crystals, Micaceous Masses
- Cleavage
- Perfect Basal
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Alkaline Igneous Rocks, Carbonatites
- Typical price
- $20-100 per specimen
Where rockhounds find fluorotetraferriphlogopite
Classic worldwide localities
- Kovdor Massif (Russia)
- Iron Mountain (USA)
Field-hunting tip
Look in alkaline igneous rocks, carbonatites country, the host setting where fluorotetraferriphlogopite typically forms. If you start seeing magnetite, apatite, calcite in float, you are in the right ground. Field specimens usually show a platy crystals, micaceous masses habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify fluorotetraferriphlogopite?+
Where is fluorotetraferriphlogopite found?+
How much is fluorotetraferriphlogopite worth?+
What rocks look like fluorotetraferriphlogopite?+
What minerals are found with fluorotetraferriphlogopite?+
What kind of rock does fluorotetraferriphlogopite form in?+
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