Just discovered Rachel Phillips' lectures on youtube, and want to recommend them for everyone interested in #geology and #opticalmineralogy (or #petrography).

My head is spinning almost as much as my mortar samples when I try to handle them under the microscope, so it's nice to break things down and go back to the basics every now and then.

https://www.youtube.com/watch?v=rTI6KypQTJk