Introduction: Identifying minerals is an important part of working in the field. Knowing the minerals that make up a rock provides clues to the type of rock and its formation history and environment. Lab analysis is used to exactly identify minerals. However, this process is not practical when you are in the field and need to quickly identify a mineral. Instead, geologists examine the properties of the mineral and compare them to established properties listed in field books and mineral charts.

 

One of the most useful properties to identifying a mineral is its hardness. Mineral hardness is found by doing a series of scratch tests. When one mineral is scratched against a second mineral, the harder mineral will leave a scratch on the softer mineral. A set of ten reference minerals ranked from one (softest) to ten (hardest) is used to establish mineral hardness. This is called Mohs Hardness Scale.

Directions for This Lesson: In this lesson, you will learn about mineral hardness. First, try the practice questions. Then, watch the video lesson.