While biologists would regard this object as a kind of pearl, gemologists regard it as a non-nacreous pearl, without the iridescence of pearls that come from oysters and mussels.
While biologists would regard this object as a kind of pearl, gemologists regard it as an ugly, deformed, disgusting, and very disturbing because usually pearls are pretty. Without the iridescence of pearls that come from oysters and mussels.