This diagram shows a variety of a different grain shapes, 12 in total. These are aligned in two rows of six. The top row is labelled ‘high sphericity’. The bottom row is labelled ‘low sphericity’. Each two-grain column is also labelled. These labels are, from left to right, ‘very angular’, ‘angular’, ‘sub-angular’, ‘sub-rounded’, ‘rounded’, ‘well-rounded’.