laterite
LAT-er-ite
A hard, iron-rich, reddish soil or rock formed in tropical and subtropical regions where intense weathering and heavy rainfall have leached away most soluble minerals, leaving behind insoluble iron and aluminum oxides. Laterite gives the tropics their characteristic red earth. When exposed to air, it hardens irreversibly — a property that has been exploited for centuries as a building material. The temples of Angkor Wat are built on laterite foundations.
Etymology
Latin later, a brick. The soil that becomes its own brick.
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