Laterite refers to both a rock and a soil type that is rich in clay, as well as Iron and Aluminium. It is created during a process that is called laterization, where high heat and seasonal heavy rainfall cause there to be wet and dry periods, which over time hardens the soil into rock. Because of this, most laterite is formed between tropics of Cancer and Capricorn. The iron oxide in laterite is what gives it it’s orange-red colouring. The largest religious complex in the world, Angkor Wat in Cambodia, is partially constructed of laterite, particularly its foundations, as laterite is porous and allows rainwater to drain.
This specimen of laterite was collected from the Democratic Republic of Congo while it was colonised by Belgium in the 19th century.
Laterite forms in many parts of the world, particularly between the tropics. It is used both for ore and as a building material, and comparing specimens from different parts of the world allows us to document the different compositions that this mineral can have when formed at different locations.
This specimen is part of a larger collection of geological and mineral specimens collected from around Australia (and some parts of the world) and donated to the Burke Museum between 1868-1880. A large percentage of these specimens were collected in Victoria as part of the Geological Survey of Victoria that begun in 1852 (in response to the Gold Rush) to study and map the geology of Victoria. Collecting geological specimens was an important part of mapping and understanding the scientific makeup of the earth. Many of these specimens were sent to research and collecting organisations across Australia, including the Burke Museum, to educate and encourage further study.
a palm-sized solid iron-aluminium oxide mineral specimen in shades of brown, orange and grey