Cervantite is a secondary antimony oxide mineral that typically forms as an alteration product of stibnite. It is most commonly found as earthy or crust-like coatings in oxidized ore zones, rarely as distinct acicular crystals.
Is this cervantite?
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 cervantite with a known reference. Cervantite 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: pale yellow to white.
- 3Read the lusterHold the specimen under a strong light. Luster: earthy when powdery.
- 4Match the color rangeCompare against the expected color range: yellow, yellowish orange, white, cream.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: acicular, earthy, reniform.
Often confused with
Cervantite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Cervantite leaves pale yellow to white, Stibiconite leaves light yellow; luster reads earthy when powdery on Cervantite and pearly, opaline, glassy to earthy on Stibiconite.
How to tell apart: Cervantite is noticeably harder (Mohs 4-5 vs. 2-2.5); streak differs, so Cervantite leaves pale yellow to white, Senarmontite leaves white; luster reads earthy when powdery on Cervantite and resinous to subadamantine on Senarmontite.
How to tell apart: Cervantite is noticeably harder (Mohs 4-5 vs. 2.5-3); streak differs, so Cervantite leaves pale yellow to white, Valentinite leaves white; luster reads earthy when powdery on Cervantite and adamantine, pearly on cleavages on Valentinite.
Often found alongside cervantite
Minerals reported to co-occur with cervantite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Sb₂O₄
- Mohs hardness
- 4-5
- Density
- 6.4-6.6 g/cm³
- Streak
- Pale yellow to white
- Luster
- Earthy when powdery
- Transparency
- Semitransparent
- Crystal system
- Orthorhombic
- Crystal habit
- Acicular, earthy, reniform
- Cleavage
- {001}, excellent; {100}, distinct
- Rarity
- Uncommon
- Uses
- Collector
- Host rock
- A secondary mineral formed from the oxidation of stibnite
Where rockhounds find cervantite
1 mapped spotsClassic worldwide localities
- Zajača-Stolice district, Brasina, Serbia
- Baia Sprie (Felsőbánya), Romania
- Cetine mine, 20 km southwest of Siena, and the Pereta mine, Scansano, Tuscany, Italy
- Clara Mine, near Oberwolfach, Black Forest, Germany
- Pocca, Bolivia
Field-hunting tip
Where it forms: A secondary mineral formed from the oxidation of stibnite. If you start seeing stibnite in float, you are in the right ground. Typical habit: acicular, earthy, reniform. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in South Dakota. Start trip planning there.
Common questions
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Find cervantite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
