Abstract: Apparatus and associated methods may relate to customizable jewelry having user-interchangeable modules. In an illustrative embodiment, the jewelry may be a ring. For example, the interchangeable module may be a substantially-rigid semi-annulus structure removably coupleable to the cylindrical annulus of the ring between about 90 and 180 degrees of the shank circumference. The shank may include a mounting portion having a semi-annular thinned region for receiving the module. In some examples, the module may couple to the shank through a reluctance force. In some examples, the module may include alignment features for preventing unwanted movement relative the shank. For example, the module may include alignment features along a peripheral edge to couple with complementary alignment features of the mounting portion. The module may characterize a user's personality, such as for example include customizable designs, colors, slogans, or pay tribute to a particular country, sport, hobby, or event.