Ask-A-Geologist #8: What is obsidian rock used for?

Hi everyone! Today I am back with another fabulous question from one of our readers. Today’s question is about obsidian. John asks: What is obsidian rock used for?

Ask-a-Geology Question & Answer #1: How Much Chemistry is Involved in Geology?

Every week we get great questions from our friends about the science and study of geology. In this new series I’m going to answer your questions so keep them coming in! This question is from Alexandra, she writes: How much chemistry is involved in geology? I’m not that great at chemistry but I’m very interested in geology.