The Versatility of a Simple Box of Random Rocks for In-Person and Online Instruction

Tuesday 1:30pm-2:40pm CC Building Circadian
Share-a-thon Part of Tuesday


LeAnne Teruya, San Jose State University


A box of random rocks with the set-up for the rounding and porosity/permeabiity activities will be shown along with the online version of the activities using Jamboard.


This activity will demonstrate several ways in which a simple box of random rocks can be used in a variety of ways for hands-on learning about composition and texture in rocks, and rounding, porosity, and permeability. Using photos of rocks and Google Jamboard, most of these activities can be done in an online environment, also.


Random Rocks activities are ideal for use in introductory geology courses. The first goal is for students to practice observing and to connect their observations with geological knowledge. The first random rocks assignment is for students to divide a random scoop of rocks into groups. There are no rules and the only guideline is that the students must have a reason for the groupings. The results lead to a class discussion of what color and texture tell us about rocks, as this is how the students most commonly divide their rocks. The second use of the random rocks is when students are learning about weathering and erosion. The goal is for students to apply their knowledge to actual rocks. Students are asked to line up their rocks according to roundedness—from angular to rounded. In another use, the students will test the random rocks for porosity and permeability, learning distinguish between the two concepts. Random rocks can also be used to teach about grain size, to distinguish between intrusive and extrusive igneous rocks, and to identify felsic verses mafic rocks.

Why It Works

Having one box of rocks with several uses simplifies preparation for activities. These activities do not require pre-sorting or labeling of rocks--another time saver! In addition, the use of found rocks can make this an extremely low-cost teaching tool. These activities are effective because they allow students both in-person and online to apply their knowledge directly to rock samples.