Yes they are man made..
rocks.
natural .................................GHO$T
Rocks are just made. They aren't made for any reason other than by the natural circumstances of the Earth.
Trade made Great Zimbabwe's rulers wealthy and powerful.
One natural substance found in rocks is quartz, which is a mineral made up of silicon and oxygen atoms. Another natural substance found in rocks is calcite, a mineral made up of calcium carbonate. Other substances like feldspar, mica, and olivine can also be found in rocks.
The southern parts of Zimbabwe, Zimbabwe is a country.
sedimentary
A rock is made of 2 or more minerals, minerals make up rocks but rocks cannot make up minerals.
Trade made Great Zimbabwe's rulers wealthy and powerful.
Natural objects include anything that was not made by people; examples include trees, rocks, mountains, clouds, the moon, etc.
minerals
Diamonds are made from carbon, and are called rocks sometimes in their raw, natural form.