When they were wee, the four Pie sisters loved to share their mutual affection for the earth around them, or, more namely, rocks. While the four were often at odds, they could bond over the only pets they were allowed to have.
 
Maud, of course, loves her little basalt pebble Boulder. Marble adores her amethyst geode Sparkles, Limestone prefers something a little intense like her obsidian chunk of obsidian named Dragonglass (referencehuehuereference) and Pinkie, of course, is quite attached to Sweetums, a candy rock no less.
 
Workin’ at backgrounds and such. I fucking hate backgrounds.