While they display a range of colors and can be found in many different kinds of rocks, feldspars have a very consistent set of physical properties. For example, they are all fairly hard and break cleanly in two directions. This is ultimately due to their chemistry.
Below we'll learn how the major feldspar groups are categorized, then explore three important feldspar minerals. And the next time you see a stone countertop, look closely. I'd expect you'll find one of these three minerals in it. Let's explore!