A: Scarab. Around, at the top: characteres, below: inscription in three lines:
ιαιδαθιανν|[.]ηφιδιωκνη|ιιωι → unidentified voces. The gem was made smaller, at a later date, part of the letters were polished off.
B: Plain.
Bibliography:
Michel, BM on CBd-501
The British Museum Collection database on CBd-501