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, 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.
