composed of parallel strata
• (a.) Characterized by the presence of thin parallel strata, or layers, as in an agate.
Stra·tic'u·late adjective [ Dim. Fr. stratum .] (Min.) Characterized by the presence of thin parallel strata, or layers, as in an agate. 
straticulate, straticulation 1. Used to describe a rock formation that is made up of thin layers. 2. Arranged in thin layers.