Limonite is a mixture of hydrated iron oxide minerals, primarily goethite, and lacks a defined crystal structure. It is frequently identified by its characteristic yellowish-brown streak and typically forms in earthy, botryoidal, or massive crusts in the weathering zones of iron deposits.
Is this limonite?
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 limonite with a known reference. Limonite sits at Mohs 4-5.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Limonite leaves a yellowish-brown streak.
- 3Read the lusterHold the specimen under a strong light. Limonite typically shows a submetallic to earthy luster.
- 4Match the color rangeCompare against the expected color range: yellow, brown, reddish-brown, black.
- 5Look at form & habitCrystal system: amorphous. Typical habit: massive, botryoidal, stalactitic, earthy.
Often confused with
Limonite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Limonite leaves yellowish-brown, Iron Ore leaves reddish-brown to black; luster reads submetallic to earthy on Limonite and metallic to submetallic on Iron Ore.
How to tell apart: Streak differs — Limonite leaves yellowish-brown, Sphalerite leaves white to yellow-brown; luster reads submetallic to earthy on Limonite and resinous to submetallic on Sphalerite.
Often found alongside limonite
Minerals reported to co-occur with limonite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- FeO(OH)·nH₂O
- Mohs hardness
- 4-5.5
- Density
- 2.7-4.3 g/cm³
- Streak
- Yellowish-brown
- Luster
- Submetallic to Earthy
- Transparency
- Opaque
- Crystal system
- Amorphous
- Crystal habit
- Massive, Botryoidal, Stalactitic, Earthy
- Cleavage
- None
- Rarity
- Common
- Uses
- Pigment, Iron Ore, Collector
- Host rock
- Oxidized Zones of Iron-bearing Mineral Deposits, Sedimentary Iron Formations
- Typical price
- $5-50 for hand-sized specimens
Where rockhounds find limonite
70 mapped spotsClassic worldwide localities
- France
- Germany
- United States
- Brazil
- Russia
U.S. states with limonite
Each link opens a state-specific list of mapped rockhounding spots that produce limonite.
Field-hunting tip
Look in oxidized zones of iron-bearing mineral deposits, sedimentary iron formations country — that is the host setting where limonite typically forms. If you start seeing goethite, hematite, quartz in float, you are in the right ground. Field specimens usually show a massive, botryoidal, stalactitic, earthy habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Utah, North Carolina, Iowa — start trip planning there.
Common questions
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Find limonite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
