located. The prospecting stage generally involves mapping, geophysical survey techniques (aerial and/or ground-based surveys), geochemical sampling, Ore is natural rock or sediment that contains one or more valuable minerals, typically including metals, concentrated above background levels, and that is economically viable to mine and process. Ore grade refers to the concentration of the desired material it contains. The value of the metals or minerals a rock contains must be weighed against the cost of extraction to determine whether it is of O… Prospecting to find where an ore is located. The prospecting stage generally involves mapping, geophysical survey techniques (aerial and/or ground-based surveys), geochemical sampling, and preliminary drilling. After a deposit is discovered, exploration is conducted to define its extent and value via further mapping and sampling techniques such as targeted diamond drilling to intersect the potential ore body. This exploration stage determines ore grade, tonnage, and if the deposit is a viable economic resource. A feasibility study then considers the theoretical implications of the potential mining operation in order to determine if it should move ahead with development. This includes evaluating the economically recoverable portion of the deposit, marketability and payability of the ore concentrates, engineering, milling and infrastructure costs, finance and equity requirements, potential environmental impacts, political implications, and a cradle to grave analysis from the initial excavation all the way through to reclamation. Multiple experts from differing fields must then approve the study before the project can move on to the next stage. Depending on the size of the project, a pre-feasibility study is sometimes first performed to decide preliminary potential and if a much costlier full feasibility study is even warranted. Development begins once an ore body has been confirmed economically viable and involves steps to prepare for its extraction such as building of a mine plant and equipment. Production can then begin and is the operation of the mine in an active sense. The time a mine is active is dependent on its remaining reserves and profitability. The extraction method used is entirely dependent on the deposit type, geometry, and surrounding geology. Methods can be generally categorized into surface mining such as open pit or strip mining, and underground mining such as block caving, cut and fill, and stoping. Reclamation, once the mine is no longer operational, makes the land where a mine had been suitable for future use. With rates of ore discovery in a steady decline since the mid 20th century, it is thought that most surface level, easily accessible…