I hope I haven't offended any one ? Everything I know about gems I've learned in the last month. I bought a large collection of rocks, gems ,Simi gems,mineral s and fossils . I understand that its more likely for me to become president then surviving a daily assignation attempt for four years . Then me to have 15 quahog pearls fall in my hands. Lol Me being unable to see a core and them being purple is the only reason I looked into quahog. And because of how I bought them I really can't help with much info. Thanks for even looking at them