Inside a hollow stone, crystal facets slowly grow layer by layer. In nature, geodes form when mineralized water seeps through cavities in lava or sedimentary rock for centuries, leaving behind silica crystals — most often quartz or amethyst.
Each crystal here grows on its own cycle: first a barely visible seed appears, then the facets elongate to full form, after which the cycle repeats — procedurally simulating endless growth. Drag to rotate the camera, scroll to zoom.