This "Pearls of the Week" is from Dave LeBlanc. Dave is a researcher and owner-operator of Lagoon Island Pearl Farm near Tofino, British Columbia, Canada.
Most natural pearls form from damage to the animal, but some form as a result of illness. Dave postulates that epithelial cells that grow shell nacre may be prolapsed into the inner tissue forming nacre pockets in the body.
This "California mussel" (Mytilus californianus), displays masses of pearls due to autoimmunity from antinuclear...