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A stone guide

Limonite

Cave painters at Lascaux used limonite ochres, humanity's first yellow-brown pigment, still tinting paint today.
Iron oxide-hydroxide mixtureSpainSee treatment disclosure

Limonite is iron oxide-hydroxide mixture, FeO(OH)·nH₂O (mixture, mainly goethite). In the hand, it rates 4 to 5.5 (crusts softer) on the Mohs scale, and it runs yellow-brown and rust. The catch-all rust: earthy yellow-brown iron crusts and masses with an ochre streak, nature's most common brown stain given a name.

Family
Iron oxide-hydroxide mixture
Mohs
4 to 5.5 (crusts softer)
System
Amorphous (mixture)
Luster
Earthy to submetallic
Gravity
2.7 to 4.3
Light
Opaque
What it is

The geology.

Limonite carries the formula FeO(OH)·nH₂O (mixture, mainly goethite). It belongs to the amorphous (mixture) system. It is classified as iron oxide-hydroxide mixture.

It sits at 4 to 5.5 (crusts softer) on the Mohs scale. The surface reads earthy to submetallic. Light behaviour is opaque. Specific gravity runs 2.7 to 4.3. The streak is yellow-brown. It breaks with uneven, earthy fracture.

The catch-all rust: earthy yellow-brown iron crusts and masses with an ochre streak, nature's most common brown stain given a name.

You will most often meet it as earthy masses, pseudomorphs after pyrite cubes, bog ore lumps or stains on everything.

Where it comes from

The origins.

Everywhere iron weathers: gossans, bogs, soil; pseudomorph cubes famously from Pelham (Spain) and Utah (USA).

On value, the database notes: common; pyrite-ghost cubes are charming inexpensive collectibles.

What people work with it for

Traditional associations.

In energy work traditions, limonite has little distinct lore; it borrows general iron-mineral grounding themes.

People buy on this language, so it belongs on the page. It belongs under the facts, though, not over them.

What to look for

Spotting the real thing.

The catch-all rust: earthy yellow-brown iron crusts and masses with an ochre streak, nature's most common brown stain given a name.

Looks like How to tell them apart
Goethite Goethite is the crystalline species within limonite, fibrous structure earns the upgrade
Hematite Hematite streaks red-brown, not ochre-yellow
'Limonite' pyrite cubes Rusty cube-shaped crystals are limonite pseudomorphs, pyrite's ghost in iron rust (a collector favorite)
Check it yourself

At-home tests.

You can run every one of these at a kitchen table. Good light matters more than gear when you are looking at limonite.

Test What you should see
By eye Yellow-brown streak
By weight Earthy, often lightweight crusts
By eye Stains fingers and pockets

If these checks leave you unsure, that is what appraisers are for. Do not file, heat or soak a piece to find out.

How to live with it

Care & handling.

At 4 to 5.5 (crusts softer) on the Mohs scale this is a soft material. Keep it as a display piece, store it apart from harder stones, and skip daily-wear settings.

It breaks with uneven, earthy fracture, which is worth knowing before you set it or drop it.

Most damage happens during cleaning, not wearing. Avoid steamers, ultrasonic tanks and anything from under the sink.

For the serious reader

A deeper look.

Extended detail on composition, sourcing, authentication and market value.

The physical record

The formula on record is FeO(OH)·nH₂O (mixture, mainly goethite). Crystal system: Amorphous (mixture). Specific gravity: 2.7 to 4.3. Streak: Yellow-brown. Cleavage and fracture: Uneven, earthy fracture.

How it reaches the market

Everywhere iron weathers: gossans, bogs, soil; pseudomorph cubes famously from Pelham (Spain) and Utah (USA).

What it gets confused with

Goethite: Goethite is the crystalline species within limonite, fibrous structure earns the upgrade. Hematite: Hematite streaks red-brown, not ochre-yellow. 'Limonite' pyrite cubes: Rusty cube-shaped crystals are limonite pseudomorphs, pyrite's ghost in iron rust (a collector favorite).

What it is worth

Common; pyrite-ghost cubes are charming inexpensive collectibles.

One more thing

Cave painters at Lascaux used limonite ochres, humanity's first yellow-brown pigment, still tinting paint today.

From the Beyond Bohemian library

An education-first guide.

There is nothing to buy on this page. Limonite is not part of our catalogue, and the guide is here anyway because somebody searching the name deserves a straight answer.

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