Most of the axons in the central nervous system are wrapped in myelin, a substance rich in lipids (fatty substances) and proteins. Like the coating around an electrical wire, myelin insulates and protects the axon and helps speed nerve transmission.
Potato/Semi Round Pearls. Potato pearls are some of the less expensive freshwater pearls to be found on the market, but their look is anything but cheap. You can purchase potato pearls in every color of the rainbow, and craft beautiful one of a kind creations for gifts and your own collection.
Mother of pearl, also called nacre, is an iridescent layer of material that forms the shell lining of many mollusks. Pearl oysters and abalone are both sources of this substance, which is widely used as an inlay in jewelry, furniture, and musical instruments. Mother of pearl comes in several natural colors, but is often bleached and dyed for decorative use. The dye retains the shimmering layers which make the material so sought after.