Pyrolusite is the primary ore of manganese, frequently found as beautiful dendritic, fern-like patterns on fracture surfaces of rocks. It is characterized by its metallic luster, heavy feel, and distinctively black, powdery streak when scratched.
Is this pyrolusite?
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 pyrolusite with a known reference. Pyrolusite sits at Mohs 6-6.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Pyrolusite leaves a black streak.
- 3Read the lusterHold the specimen under a strong light. Pyrolusite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: black, bluish-black, dark gray.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: often radiating, fibrous, or dendritic; sometimes massive or powdery.
Often confused with
Pyrolusite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Pyrolusite is noticeably harder (Mohs 6-6.5 vs. 4); streak differs — Pyrolusite leaves black, Manganite leaves dark reddish-brown; luster reads metallic on Pyrolusite and submetallic on Manganite.
How to tell apart: Streak differs — Pyrolusite leaves black, Romanèchite leaves shiny brownish black; luster reads metallic on Pyrolusite and submetallic to dull on Romanèchite.
How to tell apart: Streak differs — Pyrolusite leaves black, Iron Ore leaves reddish-brown to black; luster reads metallic on Pyrolusite and metallic to submetallic on Iron Ore.
Often found alongside pyrolusite
Minerals reported to co-occur with pyrolusite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- MnO₂
- Mohs hardness
- 6-6.5
- Density
- 4.4-5.1 g/cm³
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Tetragonal
- Crystal habit
- Often Radiating, Fibrous, Or Dendritic; Sometimes Massive or Powdery
- Cleavage
- Perfect
- Rarity
- Common
- Uses
- Industrial, Collector, Ore of Manganese
- Host rock
- Sedimentary Manganese Deposits, Hydrothermal Veins, And Oxidation Zones
- Typical price
- $10-50 for small cabinet specimens
Where rockhounds find pyrolusite
31 mapped spotsClassic worldwide localities
- Ilmenau, Germany
- Groote Eylandt, Australia
- Minas Gerais, Brazil
- Batesville, Arkansas, USA
U.S. states with pyrolusite
Each link opens a state-specific list of mapped rockhounding spots that produce pyrolusite.
Field-hunting tip
Look in sedimentary manganese deposits, hydrothermal veins, and oxidation zones country — that is the host setting where pyrolusite typically forms. If you start seeing manganite, psilomelane, goethite in float, you are in the right ground. Field specimens usually show a often radiating, fibrous, or dendritic; sometimes massive or powdery habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Utah, California, Idaho — start trip planning there.
Common questions
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Find pyrolusite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
