Characteristics of minerals
Topic: Mineral Resources of India: Distribution and Conservation · NCERT: Class 12, Ch 5 "Mineral and Energy Resources"
Meaning
Minerals share three main features. First, they are spread unevenly: some regions have a lot of them and others have almost none. Second, quality and quantity are inversely related, which means high-grade ore (ore with a lot of useful metal in it) is scarce, while poor-grade ore is common. Third, minerals are exhaustible. They take millions of years to form and cannot be refilled once they are used up, so there is "no second crop". Workable deposits make up only about 1% of the earth's crust. For these reasons, minerals must be conserved.
Example
The Kolar Gold Fields in Karnataka were mined from 1880 and closed in 2001. Mining had become too deep and too costly to pay, a clear case of a mineral resource running out.
Don't confuse with
- Renewable resources: forests, water and soil can be renewed within a human lifetime. Minerals cannot.