PEARL GemShoppy March 28, 2015 Gemstones Pearl symbolizes love, success, and happiness. The colour of pearls varies with the mollusk and its environment. It ranges from black to white, with the rose of Indian pearls esteemed most. Other colours are cream, grey, blue, yellow, lavender, green, and mauve. All occur in delicate shades. Cultured pearls are being produced in virtually every colour of the rainbow. The chief component of the nacre that constitutes the pearl is aragonite CaCO. Pearls are formed by a mollusk consisting of the same material (called nacre, or mother-of-pearl) as the mollusk‘s shell. It is a highly valued gemstone. The shell-secreting cells of the mollusk are located in the mantle of its body. When a foreign particle penetrates the mantle, the cells attach to the particle and build up more or less concentric layers of pearl around it. Irregularly shaped pearls called baroque pearls are those that have grown in muscular tissue. Pearls that grow adjacent to the shell are often flat on one side and are called blister pearls. Pearls are characterized by their translucence and lustre and by a delicate play of surface colour called orient. The more perfect its shape (spherical or drop like) and the deeper its lustre, the greater its value. Only those pearls produced by mollusks whose shells are lined with mother-of-pearl (e.g., certain species of both saltwater oysters and freshwater clams) are really fine pearls. Pearls from other mollusks are reddish or whitish, porcellaneous, or lacking in pearly lustre.