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.
Oysters belong to the mollusk family, along with clams, mussels and scallops. These shellfish are commonly served raw as appetizers, smoked and canned, or breaded and deep-fried.In all these preparations, oysters offer several important nutrients the body needs. Choosing the right variety will help you reap the mollusk's benefits without a lot of added fat and calories.hese shellfish are commonly served raw as appetizers, smoked and canned, or breaded and deep-fried. In all these preparations, oysters offer several important nutrients the body needs. Choosing the right variety will help you reap the mollusk's benefits without a lot of added fat and calories.