Its ok lol, if they get banged on something they can chip, its like luminova suspended in epoxy resin or something of that nature. Not uncommon either, the earlier subs like my 1680 had tritium pearls that fell out often: And afterwards:
Actually the craft stores sell little Pearls in numerous sizes. Hey, wait a minute, didn't you tell me Wendy calls you her little pearl?? "Make my excuse to him, so please you!” answered Hester, with a triumphant smile. “I must tarry at home, and keep watch over my little Pearl."