  We introduce a class of 4-dimensional crystal melting models that count the
BPS bound state of branes on toric Calabi-Yau 4-folds. The crystalline
structure is determined by the brane brick model associated to the Calabi-Yau
4-fold under consideration or, equivalently, its dual periodic quiver. The
crystals provide a discretized version of the underlying toric geometries. We
introduce various techniques to visualize crystals and their melting
configurations, including 3-dimensional slicing and Hasse diagrams. We
illustrate the construction with the D0-D8 system on $\mathbb{C}^4$. Finally,
we outline how our proposal generalizes to arbitrary toric CY 4-folds and
general brane configurations.
