Wakabayashilite is a rare arsenic-antimony sulfide typically found as delicate, needle-like or fibrous sprays. It is highly sensitive to light and can degrade over time, making it a challenging and prized specimen for advanced collectors of arsenic minerals.
Is this wakabayashilite?
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 wakabayashilite with a known reference. Wakabayashilite sits at Mohs ~1.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: orange-yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: silky (for fibrous aggregates) to resinous.
- 4Match the color rangeCompare against the expected color range: golden yellow, lemon.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: fibrous.
Often confused with
Wakabayashilite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Wakabayashilite leaves orange-yellow, Realgar leaves red-orange to red; luster reads silky (for fibrous aggregates) to resinous on Wakabayashilite and resinous to greasy on Realgar.
How to tell apart: Streak differs, so Wakabayashilite leaves orange-yellow, Pararealgar leaves bright yellow; luster reads silky (for fibrous aggregates) to resinous on Wakabayashilite and vitreous to resinous on Pararealgar.
How to tell apart: Streak differs, so Wakabayashilite leaves orange-yellow, Orpiment leaves pale lemon-yellow; luster reads silky (for fibrous aggregates) to resinous on Wakabayashilite and resinous, pearly on cleavage surface on Orpiment.
Often found alongside wakabayashilite
Minerals reported to co-occur with wakabayashilite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (As,Sb)₁₁S₁₈
- Mohs hardness
- ~1.5
- Density
- 3.96 g/cm³
- Colors
- Streak
- Orange-yellow
- Luster
- Silky (for fibrous aggregates) to resinous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Fibrous
- Cleavage
- {100}, {010}, {101}, perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- As fibers in druses of quartz or embedded in calcite
Where rockhounds find wakabayashilite
Classic worldwide localities
- White Caps and Black Mammoth mines, Manhattan district, Nye Co., and in the Getchell mine, Potosi district, Humboldt Co., Nevada, USA
- Nishinomaki mine, Gumma Prefecture, Japan
- Jas Roux deposit, 10 km east of Chapelle-en-Valgaudemar, Hautes-Alpes, France
- Gal-Khaya deposit, Sakha, and from the Lukhumi arsenic deposit, central Caucasus Mountains, Russia
- Khaydarkan, Fergana Valley, Alai Range, Kyrgyzstan
- Shuiluo arsenic deposit, Zhuang district, Guangxi Autonomous Region, China
Field-hunting tip
Where it forms: As fibers in druses of quartz or embedded in calcite. If you start seeing realgar, orpiment, stibnite in float, you are in the right ground. Typical habit: fibrous. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify wakabayashilite?+
Where is wakabayashilite found?+
Is wakabayashilite safe to handle?+
What rocks look like wakabayashilite?+
What minerals are found with wakabayashilite?+
What kind of rock does wakabayashilite form in?+
What is wakabayashilite used for?+
Find wakabayashilite on the map
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