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. Cervantite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Cervantite typically shows a earthy luster.
- 4Match the color rangeCompare against the expected color range: yellow, white, gray.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: acicular crystals, earthy or massive crusts, pseudomorphs after stibnite.
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 white, Stibiconite leaves light yellow; luster reads earthy on Cervantite and pearly to earthy on Stibiconite.
How to tell apart: Cervantite is noticeably harder (Mohs 4-5 vs. 2.5); luster reads earthy on Cervantite and resinous to subadamantine on Senarmontite.
How to tell apart: Cervantite is noticeably harder (Mohs 4-5 vs. 2.5-3); luster reads earthy on Cervantite and adamantine 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
- 6.64 g/cm³
- Streak
- White
- Luster
- Earthy
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Acicular Crystals, Earthy or Massive Crusts, Pseudomorphs After Stibnite
- Cleavage
- {001}, Excellent; {100}, Distinct
- Rarity
- Uncommon
- Uses
- Collector
- Host rock
- Oxidized Zones of Antimony Deposits
Where rockhounds find cervantite
1 mapped spotsClassic worldwide localities
- Cervantes, Spain
- Kern County, California, USA
- Hunan, China
- Broken Hill, Australia
Field-hunting tip
Look in oxidized zones of antimony deposits country, the host setting where cervantite typically forms. If you start seeing stibnite, valentinite, kermesite in float, you are in the right ground. Field specimens usually show a acicular crystals, earthy or massive crusts, pseudomorphs after stibnite habit, so 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.
