Sarabauite is a very rare antimony-calcium sulfide mineral known primarily from the Sarabau mine in Malaysia. It typically occurs as small, distinctively tabular, dark red crystals that show a strong adamantine luster. Collectors prize it for its unique chemistry and extreme rarity, usually appearing in association with other antimony minerals.
Is this sarabauite?
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 sarabauite with a known reference. Sarabauite 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: orange.
- 3Read the lusterHold the specimen under a strong light. Luster: resinous.
- 4Match the color rangeCompare against the expected color range: carmine red, red.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals, platy aggregates.
Often confused with
Sarabauite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Sarabauite is noticeably harder (Mohs 4.5 vs. 2); streak differs, so Sarabauite leaves orange, Stibnite leaves lead-gray; luster reads resinous on Sarabauite and metallic, splendent on cleavage surfaces on Stibnite.
How to tell apart: Sarabauite is noticeably harder (Mohs 4.5 vs. 1-1.5); streak differs, so Sarabauite leaves orange, Kermesite leaves brownish red; luster reads resinous on Sarabauite and adamantine to semimetallic on Kermesite.
Often found alongside sarabauite
Minerals reported to co-occur with sarabauite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaSb₁₀O₁₀S₆
- Mohs hardness
- 4.5
- Density
- 4.8 g/cm³
- Colors
- Streak
- Orange
- Luster
- Resinous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular crystals, platy aggregates
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In hydrothermal mineral deposits, deposited at high temperature
Where rockhounds find sarabauite
Classic worldwide localities
- Sarabau mine (type locality) and the Lucky Hill mine, Bau district, about 40 km southwest of Kuching, Sarawak, Malaysia
Field-hunting tip
Where it forms: In hydrothermal mineral deposits, deposited at high temperature. If you start seeing stibnite, sénarmontite, wollastonite in float, you are in the right ground. Typical habit: tabular crystals, platy aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
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Find sarabauite on the map
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