Yoshimuraite is a rare barium-manganese titanium silicate mineral typically found in metamorphic manganese deposits. Collectors should look for its distinctive yellow-brown tabular or bladed crystals associated with other manganese minerals like rhodochrosite.
Is this yoshimuraite?
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 yoshimuraite with a known reference. Yoshimuraite sits at Mohs 4.5, 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: orange brown.
- 5Look at form & habitCrystal system: triclinic. Typical habit: tabular crystals, bladed, lamellar aggregates.
Often confused with
Yoshimuraite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Yoshimuraite leaves white, Seidozerite leaves yellow-brown.
How to tell apart: Baotite is the harder of the two (Mohs 6 vs. 4.5); luster reads vitreous on Yoshimuraite and nearly semimetallic to vitreous on Baotite.
Often found alongside yoshimuraite
Minerals reported to co-occur with yoshimuraite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ba₄Mn₄Ti₂(Si₂O₇)₂(PO₄)₂O₂(OH)₂
- Mohs hardness
- 4.5
- Density
- 4.13-4.20 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent to translucent
- Crystal system
- Triclinic
- Crystal habit
- Tabular crystals, bladed, lamellar aggregates
- Cleavage
- Perfect on {010}, distinct on {101}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In the border facies of an alkalic pegmatite cutting a stratiform manganese deposit (Noda-Tamagawa mine, Japan)
Where rockhounds find yoshimuraite
Classic worldwide localities
- Noda-Tamagawa mine, Tamagawamura, and the Hijikuzu mine, Iwate Prefecture, and the Taguchi mine, Shidara, Aichi Prefecture, Japan
Field-hunting tip
Where it forms: In the border facies of an alkalic pegmatite cutting a stratiform manganese deposit (Noda-Tamagawa mine, Japan). If you start seeing richterite, rhodonite, barian potassic feldspar in float, you are in the right ground. Typical habit: tabular crystals, bladed, lamellar aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify yoshimuraite?+
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What rocks look like yoshimuraite?+
What minerals are found with yoshimuraite?+
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Find yoshimuraite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
