Hard stone, Mohs 7. Microcrystaline variety of quartz, most often with banding. Probably imported in the Aegean.
Aegean Seals and Sealing
 
Alabaster
Soft stone, Mohs 7.
Aegean Seals and Sealing
 
Amygdaloid
Elongated biconvex seal perforated through the long axis. It takes its name from its general resemblance to an almond (the Greek αμύγδαλο). Amygdaloids are, however, symmetrical and most often have two blunt edges perforated by the stringhole. Popular in the Late Bronze Age.