A jewelry assembly comprises a shank (30, 70, 110, 156, 172, 198) and a collet (10, 50, 108, 150, 164, 186) and a locking element (26, 28, 46, 48, 64, 66, 92, 94, 105, 107, 152, 162, 166, 170, 182, 184, 196, 202) on each of the collet (10, 50, 108, 150, 164, 186) and shank (30, 70, 110, 156, 172, 198) arranged to mechanically cooperate to hold the collet (10, 50, 108, 150, 164, 186) and shank (30, 70, 110, 156, 172, 198) in a predetermined relative position. Two locking elements (26, 28, 46, 48, 64, 66, 92, 94, 105, 107, 152, 162, 166, 170, 182, 184, 196, 202) may be provided on each side of the collet which are rounded protrusions and which cooperate with corresponding holes in the shank.