This Instagram sensation started as a simple post. In 2016, Denver-based cake maker and Food Network Challenge winner Rachael Teufel was asked to create a cake inspired by an amethyst. She came up with a rock candy geode and shared a photo, and everyone went nuts. Now, with more than 48,000 posts, #geodecake is officially a thing: Beyoncé celebrated her birthday with a black-and-gold one. See how Rachael creates this gem.

All photographs by Rachael Teufel, Intricate Icings Cake Design.