key terms

• Mineral - something that can be mined from the ground and is of economic value. 
• Ore - rock containing valuable metals 
• Ore mineral - the mineral from which valuable component usually a metal will be derived. 
• Gangue mineral - the unwanted part of the ore, made of minerals like calcite, quartz and iron pyrite. 
• Grade refers to the proportion of the ore that the ore mineral or actual elemental metal content that can be extracted from it  - expressed as a percentage.  
• Cornish tin ore grade is between 0.5-1.5% of wanted material. 
• Concentration factor is the amount by which the metal is concentrated to make an ore deposit.
• Concentration factor = concentration of metal in ore / average crustal abundance. 
• Tonnage - the total amount of metal that can be extracted from any particular ore deposit.