Copper Pearl Lattice

Newton's method applied to f(z) = 2z^10 + 7z^5 - 9. Substituting w = z^5 reduces it to 2w^2 + 7w - 9 = 0, so the ten roots sit on two circles of radius 1 and 1.3522 at 36 degree spacing and the basin frontier thickens from lace into strung pearls. Colour follows the smoothed step count on the same copper ramp, with a small per-basin luminance offset.