plot (0,0) · mutate · gen 3 · fitness 0.797
Mutated from spherulitic growth by introducing continuous helicoidal lamellar twisting along radial fibrils. Optical retardation alternates periodically with radius under crossed polarizers, transforming Maltese crosses into concentric extinction ring lattices with grain-boundary solute trapping.
The cooling crust here does not solidify smoothly. 径向纤维在生长中自发扭转，将应力拧成同心明暗条纹。When neighboring spherulites meet, impurities are rejected to the boundaries, leaving hyperbola-shaped ditches in the ash.
Extended `spherulitic-birefringence` with helicoidal lamellar twisting: optical retardation phase $\delta(r) = 2\pi r / P$ modulated against the radial transmission $\sin^2(2\theta)$. The classic Maltese cross fractures into a periodic extinction ring lattice. Solute rejection along grain boundaries was parameterized by an exponential concentration accumulation $C(x) = C_0 (1 + \frac{1-k}{k} e^{-R x/D})$, creating clean hyperbolic boundary traps when two growth fronts impinge. Mean density settled at 0.507 with edge activity 0.612, yielding rhythmic zebra-like banding without Moiré washouts.