Noun
(geology) a constituent fragment of a clastic rock
Source: WordNetThe subdivision of these three broad categories is based on differences in clast shape: conglomerates and breccias ), composition ( sandstones ), grain size and/or texture ( mudrocks ). Source: Internet
The form of a clast can be described by using four parameters: Levin (1987), p. 60 Blatt et al. Source: Internet