This video shows some impressions of our January 2010 field work in Oman. For more information: www.ged.rwth-aachen.de or bit.ly/FRACs The main aim of this project is to understand the role of existent veins, which act as heterogenities to fracturing depending on orientation and their sealing-driven strength regeneration. Secondly, to understand the growth of crystals from oversaturated fluids in fractures is the other major aim of this project. Crystal growth appears as a back-coupled system with fluid flow and material transport in fractures. The growth of crystals and the growth of the vein respectively is influenced by the stress state in the system as this might open the fracture again. This study is carried out within the framework of DGMK (German Society for Petroleum and Coal Science and Technology) research project 718 "Mineral Vein Dynamics Modelling", within the basic research programme of the WEG Wirtschaftsverband Erdöl- und Erdgasgewinnung eV We thank the companies for their finacial support and their permission to publish our results.