There are two ways to remove coal from the ground: surface mining and underground mining. Surface mining is used when a coal seam is relatively close to the surface, usually within 200 feet. The first step in surface mining is to remove and store the soil and rock covering the coal (called the overburden).
Pearl oysters are not closely related to true oysters, being members of a distinct family, the feathered oysters (Pteriidae). Both cultured pearls and natural pearls can be extracted from pearl oysters, though other molluscs, such as the freshwater mussels, also yield pearls of commercial value.
Summary of Food Sources. The most well-known fact about zinc in foods is almost certainly that oysters are rich in zinc. A typical oyster weighing approximately one ounce will contain about 8-9 milligrams of zinc. So two oysters would put you over the WHFoods recommended daily amount of 11 milligrams.he most well-known fact about zinc in foods is almost certainly that oysters are rich in zinc. A typical oyster weighing approximately one ounce will contain about 8-9 milligrams of zinc. So two oysters would put you over the WHFoods recommended daily amount of 11 milligrams.