Porous ceramics have interesting properties for several applications. For instance, porous calcium carbonate could be applied for thermal cycle energy storage, carbon capture and storage, bone scaffolds, artificial corals, and rock replicas. Additive manufacturing, especially vat-photopolymerization, has been proposed as an interesting alternative to produce porous media due to its high geometrical reproducibility and superior resolution. However, concerning calcium carbonate, this process has two main challenges. First, CaCO₃ thermally decomposes at about 550°C in air, which is a challenge for debinding and subsequent sintering. Second, it is difficult to remove the organics during the debinding of photocured ceramic parts. Therefore, the evolved gases should be released very slowly to avoid cracking the fragile ceramic matrix. This constraint limits the wall thickness of photocured ceramic parts to about 10 mm, which is insufficient for some applications, such as rock replicas (usually much larger). As a possible solution, this study proposes casting a composite of calcite with geopolymer into a soluble water-soluble mold produced by vat-polymerization. The methodology was divided into four steps. 1) A casting suspension containing calcium carbonate and a metakaolin-based geopolymer was formulated. Then, the rheology and setting time of the suspension were characterized. The ceramic content, particle size, water amount, and rheology modifiers were adjusted for proper castability. 2) The soluble sacrificial molds were produced using a water-soluble photocurable resin through vat-photopolymerization. The printing parameters (layer thickness and exposure time) were optimized, and the minimum size of the printed features (holes, channels, and struts) was defined with the aid of SEM imaging. 3) The calcite + geopolymer composites were cast in the soluble molds. The mold was removed in different conditions (simple immersion, ultrasonication, and forced flow) to evaluate the better strategy of proper material removal in the inner channels. The drying temperature and time were also adjusted. Also, the crystalline phases present after the thermal treatment were evaluated with X-ray diffraction. 4) Finally, the parts were characterized concerning their microstructure, mechanical strength, density, BET surface area, and porosity. The great advantage of the presented methodology is combining the benefits of two technics. On the one hand, the geopolymer allowed the consolidation of the calcium carbonate at low temperatures, avoiding the problems related to debinding and sintering. It also allowed larger parts to be produced. On the other hand, using additive manufacturing to fabricate the mold had the advantage of high resolution and the ability to replicate complex digital geometries. The applicability of the produced samples for rock replicas and artificial corals was evaluated and discussed, highlighting the advantages and current limitations of the proposed methodology. In particular, the pros and cons of the technic were compared to the direct manufacturing of porous calcite parts using vat-photopolymerization.