This dataset depicts the phase segmentation results for the representative XY-sliced images from scan 3, where the carbonate saturation levels are denoted by color variation. The sand pixels are depicted in brown, while void in black. The remaining carbonate pixels were categorized into the following six classes based on the their CaCO3 saturation levels (Scc): (a) Scc = 0% (i.e., air void pixel), (b) 0% < Scc < 25%, (c) 25% ≤ Scc < 50%, (d) 50 ≤ Scc < 75%, (e) 75% ≤ Scc < 100%, and (f) Scc = 100%, in which the pixels are completed filled with CaCO3.