gabbro

gabweb Originally uploaded by kevinzim I have a confession to make: I have absolutely no idea what this picture means. And most of you probably don't either, which is okay, because you're not running around the Internets pretending to be a geologist. This is what's colloquially known as a thin section - a piece of rock sliced so thin that you can shine light through it, and then stare at it under a microscope until you get a headache. Minerals that look similar in a hand sample will refract light very differently in thin section, which makes it useful for obsessive mineral-identifiers.…