Why Do They Add The Stone?

What’s the point of putting a stone on top when growing bismuth crystals?” “I mean, does it actually change the pattern of the crystal?” “You might’ve seen videos where bismuth forms those geometric shapes as it cools and solidifies. That happens because the outer parts cool faster than the center, forming that hollow, stair-step structure.” “Now, people drop all kinds of stones on top—and it’s easy to misinterpret what’s going on.” “The stone just acts as a seed, or nucleation point. It gives the bismuth a solid spot to start cooling and forming crystals, but the pattern is always random.