Vessem is one of the many groundwater protections areas in Noord Brabant, the Netherlands, under the control of Brabant Water. A vulnerable area where the region’s tap water is sourced. The water is extracted from sources of dozens of meters deep, and is about 50 to 200 years old. Most of the oxygen in the water is already disappeared, and metals like manganese and iron are dissolved. It is here where centuries ago the Romans harvested iron ore in order to make knives and axes. And nowadays for us the perfect place to harvest the iron ore to develop our project ‘Oer’. We visited the place several times and took samples of different residues, such as dried out iron ore and iron ore which is diluted with water. This solid residual can be characterized by its deep red color. Because of the difference in the percentage of iron ore every time, we had the opportunity to developed different colors and textures. The coloring of porcelain is our first tangible result of this research.