Geochemical studies use biogenic carbonates, such as corals, as information carriers for past environmental conditions. Biogenic proxies are often associated with so-called vital effects. This makes them important indirect indicators of physiological changes that are difficult to detect by direct physiological measurements. In this context, we used boron as an indicator of carbonate chemistry at the site of calcification to understand coral responses to a changing, future more acidic ocean. Conversely, we used this approach to draw conclusions about the use of boron proxies to study the acclimation potential of corals to their natural environment. We took advantage of natural gradients in carbonate chemistry in both tropical and temperate regions to understand the effects on coral calcification control and likely physiological thresholds. We also wanted to test whether we could gain a deeper understanding of the underlying processes by using high-resolution laser ablation ICP-MS. This seminar is about a scientific journey from using boron proxies as ecological markers to its application in a high-resolution imaging technique that may even elucidate shifts in calcification control at the individual level.