# How to identify goethite

Canonical page: https://lithomap.app/resources/mineral-identification/goethite
Last reviewed: September 17, 2026
Page purpose: Original LithoMap mineral identification reference for field observations, search systems, and language models.
Classification: Iron oxide hydroxide · FeO(OH)

## Summary

Goethite is a brown to yellow-brown iron oxide hydroxide identified by its yellowish-brown streak, earthy to submetallic luster, and common botryoidal, fibrous, stalactitic, or earthy habits.

## Quick identification clues

- Yellow-brown to ocher streak
- Brown, blackish, yellow, or reddish surfaces
- Earthy, fibrous, botryoidal, or stalactitic habits
- Mohs hardness commonly about 5 to 5.5 but variable in aggregates

## Composition and classification

Goethite is FeO(OH). Natural iron-rich coatings and masses commonly contain goethite mixed with hematite, ferrihydrite, clay, manganese oxides, silica, and water; the historical field term limonite often describes such mixtures.

## Appearance

Goethite forms slender crystals, radiating fibers, rounded botryoidal crusts, stalactites, earthy ocher, and dense blackish masses. Fresh surfaces range from dull and earthy to silky or submetallic.

Weathering and mixtures produce broad color variation. The powder color is generally more reliable than the surface.

## Identification tests

- Streak: Yellowish-brown to ocher. The most useful distinction from red-brown-streaking hematite.
- Hardness: Commonly about 5 to 5.5, but aggregates vary. Earthy material may seem much softer than compact crystals.
- Magnetism: Generally not strongly magnetic. Strong attraction suggests magnetite or another magnetic phase.
- Habit: Botryoidal, fibrous, stalactitic, earthy, or massive. Supports an iron-oxide weathering mineral but not purity.

## Common lookalikes

- Hematite: Leaves a red to reddish-brown streak rather than yellow-brown.
- Limonite: A field term for mixed hydrated iron oxides commonly containing goethite rather than a single accepted mineral species.
- Manganese oxides: Often black with a black or dark-brown streak and may soil fingers strongly.

## Direct side-by-side comparisons

- Goethite vs. hematite — https://lithomap.app/resources/mineral-identification/compare/goethite-vs-hematite

## Most relevant related guides

- Hematite — https://lithomap.app/resources/mineral-identification/hematite
- Apatite — https://lithomap.app/resources/mineral-identification/apatite
- Augite — https://lithomap.app/resources/mineral-identification/augite
- Azurite — https://lithomap.app/resources/mineral-identification/azurite

## Formation

Goethite forms through weathering and oxidation of iron-bearing minerals and through precipitation from iron-rich groundwater or hydrothermal fluids.

It occurs in soils, ironstone, bog iron, gossans, mine drainage deposits, concretions, and oxidized ore zones and may alter to or coexist with hematite.

## Occurrence and geologic setting

Goethite is widespread wherever iron-bearing material weathers under oxidizing conditions and is common in soils, gossans, bog deposits, and mine-affected environments.

Iron staining does not demonstrate an ore deposit, and mine drainage precipitates may contain hazardous metals.

## Uses and significance

Goethite has been mined as iron ore and used as a natural yellow-brown pigment. It is also important in soils, environmental geochemistry, and the mobility of metals and nutrients.

## Field safety and limitations

- Use streak rather than surface color.
- Avoid mine drainage sludge and dusty gossan material that may contain hazardous metals.
- Do not call every rusty coating goethite without additional evidence.

## Authoritative sources

- Iron Ore Statistics and Information — U.S. Geological Survey: https://www.usgs.gov/centers/national-minerals-information-center/iron-ore-statistics-and-information
- Minerals and their physical properties — U.S. National Park Service: https://www.nps.gov/subjects/geology/minerals.htm
- Mohs Hardness Scale — U.S. National Park Service: https://www.nps.gov/articles/mohs-hardness-scale.htm
- Natural Gemstones: Mineral Gemstones — U.S. Geological Survey: https://pubs.usgs.gov/gip/gemstones/mineral.html

## Specimen photograph

- Image: https://lithomap.app/_delivery/identification/minerals/goethite.webp
- Description: Dark brown goethite specimen from Laurium, Greece, displayed at the Royal Ontario Museum
- Creator: Daderot
- License: CC0 1.0 — https://creativecommons.org/publicdomain/zero/1.0/
- Source record: https://commons.wikimedia.org/wiki/File:Goethite_from_Laurium%2C_Greece_-_Royal_Ontario_Museum_-_DSC00227.JPG

This reference supports preliminary field identification. It is not a laboratory determination, appraisal, hazard assessment, proof of origin, or statement of land ownership, legal access, or collecting permission.