Pearl or parasite enters a bivalve mollusk and settles inside the shell. The mollusk, irritated by the intruder, forms a pearl sac of external mantle tissue cells and secretes the calcium carbonate and conchiolin to cover the irritant. This secretion process is repeated many times, thus producing a pearl. Natural pearls come in many shapes, with perfectly round ones being comparatively rare. Typically, the build-up of a natural pearl consists of a brown central zone formed by columnar calcium carbonate (usually calcite, sometimes columnar aragonite) and a yellowish to white outer zone consisting of nacre (tabular aragonite). In a pearl cross-section
Pearl Krabs vein to "Mother of God," as a reference to the absence of Pearl's mother. His use of the phrase only when he is dismayed or shocked has led some viewers to believe something tragic happened to Mrs. Krabs. At Dragon Con in 2016, Lori Alan and Rodger Bumpass addressed Pearl's origins as their characters Pearl and Squidward. In the skit, Squidward asks Pearl if she is adopted. Pearl does not give a definite response, instead saying that she gets emotional over the topic. Later at the same event, the actors discussed the disappearance of Pearl's mother. Alan affirmed that Mrs.