Gravel
Aggregate mix
Blocks
A much bigger block with a cavity/hole going through the center.
Concrete block that weighs one tonne.
Chips
3/8" Chips. Very small stones
Regular 4" block with a 30 degree offset.
Screenings-Very dusty gravel
Regular 4" block with a 90 degree offset.
Bags
An empty big bag.
Clause 804
Regular sized blocks used for most building jobs.