Go through the words in each item below and identify the relationship which is common in most of the words.
1. a. sandstone
b. shale
c. chert
d. breccia
2. a. shale
b. hornfels
c. slate
d. phyllite
3. a. basalt
b. pegmatite
c. granite
d. diorite
4. a. igneous
b. sedimentary
c. metamorphic
d. iron
5. a. foliated
b. organic
c. clastic
d. chemical