In order to study the effect of organic surface chemistry on calcite nucleation, attachment, and growth, calcium carbonate was precipitated in the presence of various ultrathin-film organosilane-modified silicon wafers. The chemistry of the aminosilane surfaces was systematically changed by the coupling of various acidic molecules, without creating a geometric lattice of acidic functional groups. Optical microscopy, scanning electron microscopy with image analysis, and X-ray scattering were employed to characterize crystallite density and orientation normal to the surface. Calcite grown on amino-modified surfaces was produced with the equilibrium rhombohedral habit and had the [104] orientation. Surfaces of the silicon oxide, carboxylate, iminodiacetate, or phosphoramidate tended to favor the orientation of surface crystals along [001] or near the [001] axes of the crystal. Primarily this is a result of the affinity of the surface for cations, but functional-group-mediated ion ordering and/or stereochemical matching is also suggested by the much greater amount of crystal nucleation on the long-chain carboxylates when compared to short-chain carboxylates. Coupling of nitrilotriacetic acid (NTA) favored appearance of [110], [113], and [116] oriented crystals when compared to the other acid surfaces. Growth of calcite with relatively larger {110} faces was observed when the microcrystals were synthesized in the presence of freely soluble NTA. Appearance of these faces is a result of a relatively suppressed growth rate due to face-specific adsorption on the growing crystallites. Similarly, the enhancement of specific crystal surface binding by the substrate bound NTA is probably the mechanism influencing orientation of surface microcrystals. Two common structural features of the {110}, {113}, and {116} faces are the tilt of the carbonate plane at large angles from the face and the same angle of rotation of the carbonates about their 3-fold symmetry axes. That angle may enhance the ability of two NTA carboxylates to simultaneously occupy carbonate sites of these calcite faces. The fact that crystallite density and orientation are influenced by submonolayers of functional groups attests to the importance of electrostatic and stereochemical recognition of certain crystal faces even without matching of the geometric lattice.