Segnitite is a rare lead-iron arsenate mineral primarily found in the oxidized zones of lead-rich hydrothermal mineral deposits. Collectors typically search for its distinct yellow to brownish-orange rhombohedral crystals, which often form in the same cavities as wulfenite and cerussite.
Is this segnitite?
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 segnitite with a known reference. Segnitite sits at Mohs 4 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Segnitite leaves a yellowish streak.
- 3Read the lusterHold the specimen under a strong light. Segnitite typically shows a resinous luster.
- 4Match the color rangeCompare against the expected color range: yellow, yellowish-brown, brownish-orange.
- 5Look at form & habitCrystal system: trigonal. Typical habit: rhombohedral crystals, sometimes forming crusts or pseudo-cubic aggregates.
Often confused with
Segnitite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Segnitite leaves yellowish, Beudantite leaves yellow; luster reads resinous on Segnitite and vitreous on Beudantite.
How to tell apart: Streak differs — Segnitite leaves yellowish, Duftite leaves light green; luster reads resinous on Segnitite and vitreous on Duftite.
How to tell apart: Streak differs — Segnitite leaves yellowish, Mimetite leaves white; luster reads resinous on Segnitite and adamantine on Mimetite.
Often found alongside segnitite
Minerals reported to co-occur with segnitite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- PbFe₃(AsO₄)₂(OH)₅
- Mohs hardness
- 4
- Density
- 6.1-6.4 g/cm³
- Streak
- Yellowish
- Luster
- Resinous
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Rhombohedral Crystals, Sometimes Forming Crusts or Pseudo-cubic Aggregates
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Lead-zinc Ore Deposits
- Typical price
- $20-150 per specimen
Where rockhounds find segnitite
Classic worldwide localities
- Broken Hill (Australia)
- Tsumeb (Namibia)
- Mapimi (Mexico)
- Touissit (Morocco)
Field-hunting tip
Look in oxidized lead-zinc ore deposits country — that is the host setting where segnitite typically forms. If you start seeing goethite, cerussite, mimetite in float, you are in the right ground. Field specimens usually show a rhombohedral crystals, sometimes forming crusts or pseudo-cubic aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify segnitite?+
Where is segnitite found?+
How much is segnitite worth?+
Is segnitite safe to handle?+
What rocks look like segnitite?+
What minerals are found with segnitite?+
What kind of rock does segnitite form in?+
What is segnitite used for?+
Find segnitite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
