A
bornhardt is a dome-shaped, steep-sided, bald rock outcropping at least in height and several hundred metres in width. A type of
inselberg, bornhardts are typically composed of
granites or
gneisses, though occasionally formed in other rock types such as
dacite,
norite,
limestone,
sandstone and
conglomerate.
Uluru, in Central Australia, is mainly composed of sandstones, while the nearby
Kata Tjuta is composed of conglomerates. They are named after
Wilhelm Bornhardt (1864–1946), a German geologist and explorer of
German East Africa, who first described the feature. The
Sugarloaf Mountain of
Rio de Janeiro is a typical example of this landform and is the origin of the common bornhardt nickname "sugar loaf".