Geode Crystal Growth Simulator (2D)

This 2D cross-section slices a geode in half to show the mechanism a 3D render can only imply: a ring of dozens of independent crystal seeds studding the inside of a hollow rock cavity, each running its own grow-hold-reset cycle as mineralized water deposits silica layer by layer onto the wall. Every spike points inward toward the empty center, exactly as real quartz-family geode crystals do, elongating with an eased growth curve before the cycle restarts to simulate centuries of intermittent deposition compressed into seconds. Switch between amethyst, citrine, emerald, rose quartz and aquamarine to see how trace-element tinting changes the cluster's color, drag the density slider to pack the wall with more or fewer seeds, and toggle the rock shell to isolate the crystal lining on its own.