The amygdaloidal minerals of the keweenawan basalts are a great resource for teaching mineral identification skills, and the boulders contain plenty of diverse examples for students to explore in an interesting and realistic way.
Bill Rose
Professor of Petrology
15 November 2010
There are a dozen or so common minerals which occur within the gas bubbles that form when lava flows degas and cool during eruptions. The minerals formed long after eruption when hot water flowed through the rocks. They have very different physical properties of color, hardness and form, which beginning students can easily discern. This means that they can gain confidence in mineral identification skills.
