What is the ruling on glorifying (Allah) with prayer beads made from the dust of agate stone, containing a mummified ant or insect, knowing that I did not kill the insect?

The carcasses of insects that have no blood are pure and not impure, by the consensus of jurists. Therefore, there is no impediment to using a rosary (subhah) that has a dead insect inside it, unless there is a specific belief associated with it, and with the preference for glorifying Allah (tasbih) with the hand.