Igneous rocks are found in Bukit Timah, Woodlands, and Pulau Ubin island.
Granite makes up the bulk of the igneous rock.
Gabbro is also found in the area and is found in an area called Little Guilin, named for its resemblance to Guilin in South China.
Sedimentary rocks are found on the western part of Singapore, which is mainly made of sandstone and mudstones.
The rocks are mainly made up of quartzite, and also make up the Sajahat Formation.