Blue-blood pearl is produced from a polluted creature called "blue-blood soft-shelled mussel" and its scientific name is "Anodonta woodiana". Different from other mussels, the soft-shelled blue-blood mussel has only one shell on its back, so its serine (a special amino acid) content is higher, which enables it to absorb more copper ions, thus producing blue blood. Blue blood pearls are genuine, not a scam.
Please note that the above explanation is for reference only. For detailed information about blue blood beads, I suggest you consult a professional or consult relevant literature.