Opal is considered the birthstone for people born in October. Famous opals. The Olympic Australis, the world's largest and most valuable gem opal [citation needed], found in Coober Pedy; The Andamooka Opal, presented to Queen Elizabeth II, also known as the Queen's Opal
1 Carbohydrates â are required for energy. 2  Glucose, which is a monosaccharide, is the most essential source of energy in the body. 3  The brain works entirely on glucose alone. 4  When an immediate source of energy is required, glucose is converted into glycogen which is stored in the liver.
There are seven main classes of nutrients that the body needs. These are carbohydrates, proteins, fats, vitamins, minerals, fiber and water. It is important to consume these seven nutrients on a daily basis to build and maintain health.he main sources of carbohydrates are plants, e.g., starch (storage forms carbohydrate of chlorophyll containing plants), sugars, cereals, potatoes, legumes, millets, roots and other vegetables.