Ferrokinoshitalite is a rare barium-rich member of the mica group, typically found in high-grade metamorphic environments. Collectors identify it by its characteristic platy, micaceous habit and distinctive barium-rich composition which separates it from common biotite.
Is this ferrokinoshitalite?
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 ferrokinoshitalite with a known reference. Ferrokinoshitalite 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. Ferrokinoshitalite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Ferrokinoshitalite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow, brown, dark brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: platy crystals, foliated masses.
Often confused with
Ferrokinoshitalite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Luster reads vitreous on Ferrokinoshitalite and pearly on Biotite.
How to tell apart: Luster reads vitreous on Ferrokinoshitalite and pearly on Phlogopite.
How to tell apart: Luster reads vitreous on Ferrokinoshitalite and pearly on Kinoshitalite.
Often found alongside ferrokinoshitalite
Minerals reported to co-occur with ferrokinoshitalite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Ba,K)(Mg,Fe²⁺,Mn²⁺)₃(Si₂Al₂)O₁₀(OH,F)₂
- Mohs hardness
- 2.5-3
- Density
- 3.36 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Platy Crystals, Foliated Masses
- Cleavage
- Perfect Basal
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Metamorphic Rocks, Skarns
- Typical price
- $20-100 per specimen
Where rockhounds find ferrokinoshitalite
Classic worldwide localities
- Sweden
- Japan
- United States
Field-hunting tip
Look in metamorphic rocks, skarns country — that is the host setting where ferrokinoshitalite typically forms. If you start seeing quartz, feldspar, garnet in float, you are in the right ground. Field specimens usually show a platy crystals, foliated masses habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify ferrokinoshitalite?+
Where is ferrokinoshitalite found?+
How much is ferrokinoshitalite worth?+
What rocks look like ferrokinoshitalite?+
What minerals are found with ferrokinoshitalite?+
What kind of rock does ferrokinoshitalite form in?+
What is ferrokinoshitalite used for?+
Find ferrokinoshitalite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
