I posted about the home page photo being maybe changed to something more suitable. A friend Moderator at another group says this is what need to be down to change it. I am just trying to help make it look more like geology than chemistry.
The Moderator has to sign on to group.
Click on "Management" on the left of the page.
Click on "Description and Appearance"
Click on Photo "Edit" toward the bottom right of the page.
Upload a picture from his/her computer.