What is Borneo made of?

Borneo is the third largest island in the World, after Greenland and New Guinea. It is made up of 73% sedimentary rocks, 20% igneous and metamorphic rocks, and 7% volcanic rocks. The sedimentary rocks are mostly sandstone, shale and limestone, while the igneous and metamorphic rocks are mostly granite, diorite and schist. The volcanic rocks are mostly andesite and basalt. Borneo is also known for its rich mineral resources, including coal, copper, gold and diamonds.