sedimentary

Limonite/Goethite Concretion

Goethite (FeO(OH))

Hardness: 5-5.5; Color: Dark brown to ochre; Luster: Dull/Earthy; Structure: Massive or botryoidal; Gravity: 3.3-4.3

Identified July 14, 2026More sedimentary →

Get a report just like this from any photo, free.

Physical properties

Hardness: 5-5.5; Color: Dark brown to ochre; Luster: Dull/Earthy; Structure: Massive or botryoidal; Gravity: 3.3-4.3

Formed as a chemical precipitate from weathering of iron-rich minerals in soil and sedimentary layers.

Historical iron ore, source of brown/yellow pigments (ochre), and collected as mineral specimens.

Commonly known as 'bog iron,' it was a primary source of iron for various cultures before high-yield mining became common.

Identify by its dark brown color and yellow-brown streak test. Frequently found in stream beds or weathered soil zones.

Fossiliferous Sedimentary Rock

Sedimentary limestone with invertebrate fossil imprint

Sandstone or Siltstone

Arenite (if sandstone)

Sandstone

Arenite

Quartz pebble

Silicon dioxide (SiO2)

Sedimentary Sandstone

Arenite (Sedimentary Rock)

Generic Pebble / Rock Fragment

Lithic fragment / Weathered rock