Heteromorphite is a rare lead antimony sulfosalt known for its distinctive needle-like or fibrous crystal habits. Collectors should look for fine, delicate, hair-like masses that often resemble stibnite but are usually found in complex hydrothermal lead-zinc vein systems.
Is this heteromorphite?
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 heteromorphite with a known reference. Heteromorphite sits at Mohs 2.5-3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: black.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: black.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: acicular or hair-like crystals, fibrous aggregates, massive.
Often confused with
Heteromorphite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Heteromorphite leaves black, Jamesonite leaves black. grayish.
How to tell apart: Streak differs, so Heteromorphite leaves black, Stibnite leaves lead-gray.
How to tell apart: Streak differs, so Heteromorphite leaves black, Boulangerite leaves brownish.
Often found alongside heteromorphite
Minerals reported to co-occur with heteromorphite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₇Sb₈S₁₉
- Mohs hardness
- 2.5-3
- Density
- 5.73 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Acicular or hair-like crystals, fibrous aggregates, massive
- Cleavage
- Good on {112}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Of hydrothermal origin
Where rockhounds find heteromorphite
Classic worldwide localities
- Arnsberg, North Rhine-Westphalia (type locality), and Wolfsberg, Harz Mountains, Germany
- Příbram, Czech Republic
- Kara Kamar deposit, Tajikistan
- Yecora, five km west of Iglesia, Sonora, Mexico
Field-hunting tip
Where it forms: Of hydrothermal origin. If you start seeing sphalerite, plagionite, semseyite in float, you are in the right ground. Typical habit: acicular or hair-like crystals, fibrous aggregates, massive. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify heteromorphite?+
Where is heteromorphite found?+
Is heteromorphite safe to handle?+
What rocks look like heteromorphite?+
What minerals are found with heteromorphite?+
What kind of rock does heteromorphite form in?+
What is heteromorphite used for?+
Find heteromorphite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
