Laterite

Physical Properties

Hardness: 2.0-3.5 on Mohs scale (variable); Color: Rusty red, brown, or ochre yellow; Luster: Dull to earthy; Crystal Structure: Amorphous/massive; Pitted, vesicular, or pisolitic texture; High specific gravity due to iron content.

Formation & Geological History

Formed through the intense and long-term chemical weathering of underlying parent rock in hot, humid tropical climates. Soluble materials like silica are leached away, leaving behind insoluble iron and aluminum oxides.

Uses & Applications

Mainly used as a road building material and in construction as building blocks (when cut wet, they are soft, but harden upon drying). Also a source for nickel, iron, and aluminum (Bauxite) ores.

Geological Facts

The word laterite comes from the Latin word 'later', meaning brick. Many ancient temples in Southeast Asia, such as Angkor Wat, were constructed using laterite blocks because of their durability and ease of quarrying.

Field Identification & Locations

Identify by its characteristic porous, 'Swiss cheese' texture and deep red-brown staining. Frequently found in tropical regions like India, Southeast Asia, Brazil, and parts of Australia.

Identified on: 5/14/2026

Mode: Standard