Earth science !

ripple marks, mud cracks and fossils are all characteristics of:
sedimentary rocks
metamorphic rocks
igneous rocks
minerals

cherts and geodes can be found in:
granite
volcanoes
limestone
silica

these rocks are often classified by their composition and texture:
sedimentary
metamorphic
igneous
minerals

these rocks can be classified as regional or contact:
sedimentary
metamorphic
igneous
minerals

the unique characteristics of sedimentary, igneous and metamorphic rocks tell us about:
how, why and where a rock formed
hot spots around the earth
weathering
movement of inorganic materials