Digging up some rocks from two random points along the surface of the earth, you are likely to find vastly different concentrations of minerals. If it wasn't for this non-uniformity in mineral concentrations, many materials essential for electronics and other products would not be possible to accumulate. For example, silver has a concentration of 0.070 parts per million in the earth's crust. To mine silver in a uniform concentration earth, we would need to dig up and process ~15 tonnes of rock to get a single gram of silver. We will talk about the importance of mineral deposits and go through some peculiar ways in which particular materials can concentrate.