sedimentary
Laterite
Laterite (Iron- and aluminum-rich rock)
Hardness varies from 1 to 3 when moist, but can harden significantly upon exposure to air (up to Mohs 7 for iron-rich crusts). Color ranges from reddish-brown, orange, to yellowish-brown due to high iron oxide content. Luster is earthy to dull. Structure is porous, vesicular, or pisolitic.
Identified More sedimentary →
Explore Laterite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness varies from 1 to 3 when moist, but can harden significantly upon exposure to air (up to Mohs 7 for iron-rich crusts). Color ranges from reddish-brown, orange, to yellowish-brown due to high iron oxide content. Luster is earthy to dull. Structure is porous, vesicular, or pisolitic.
Formation & geological history
Formed by the intense weathering of parent rocks under strongly oxidizing and leaching conditions in wet, tropical, and subtropical climates. This process, known as lateritization, leaches out soluble minerals like silica, leaving behind insoluble oxides of iron and aluminum.
Uses & applications
Primary ore of aluminum (bauxite is a type of laterite). Used locally in developing nations as a brick-like building material (cut into blocks that harden when exposed to air) and in road construction.
Geological facts
Laterite soils cover about one-third of the Earth's land area. The term was first coined by Francis Buchanan-Hamilton in 1807 in southern India, derived from the Latin word 'later', meaning brick.
Field identification & locations
Easily identified in the field by its distinct reddish-brown color, porous or vesicular texture, and occurrence in tropical or subtropical weathering profiles. Common in India, Australia, Brazil, and parts of Southeast Asia.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Fossiliferous Concretion
Septarian Concretion containing Brachiopods/Crinoids
fossil
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Generic Pebble / Rock Fragment
Lithic fragment / Weathered rock
sedimentary
Banded Siltstone / Mudstone Pebble
Siltstone / Argillite
sedimentary
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary