Hot sand.

• Position: Oil and natural gas exploration - Brief article

Some Wisconsin sand is so highly sought after you'd think it was gold. One underground mine there scoops thousands of tons of this "frac sand" from the bluffs along the Mississippi River. It's valuable because it's as round as really tiny snowballs and super strong, and it's almost pure quartz. It's perfect for the oil and natural gas exploration industry. The sand is mixed with water and then pumped at very high...