These gems were used as amulets, but they do not belong to the category of magical gems. They usually bear an inscription such as 'diaphylasse' or 'heis theos'. For an example, see CBd-1020
These gems may also have been used as amulets, but lacking an inscription, this can only be presumed. Pieces are grouped in this category when the iconographical schemes they bear are mentioned in ancient sources, such as the Lithika,
see for example CBd-78. Gems that belong to collections with restricted access may also be grouped here, see CBd-1235 and CBd-1292.