Choose the odd one out.
Slate
Gneiss
Marble
Shale
Granite
Limestone
Pumice
Obsidian
Quartzite
Potassium
Copper
Petrol
Coal
Iron
Conglomerate
Sandstone
sedimentary
igneous
metamorphic
quartzite
fine grains of mud and clay
mineral known as calcite
large sediments like sand and pebbles
rock formed from limestone
Petroleum
Diesel
Phosphorus
Gravel
