AbstractThe Kleivan granite is an oval granite of about 20 km2 situated near Lyngdal, south Norway. Samples from the quartz veins in the top of the magma chamber have been collected to investigate whether Mo might have partitioned into these quartz veins. The means of studying the quartz veins have been by optical microscopy, SEM-CL and microthermometry. The mineral assemblage of the quartz veins consists of quartz, altered feldspars and biotite. The thin sections showing the largest fluid inclusions have been chosen for further investigation by SEM-CL and microthermometry. The SEM-CL shows the quartz as a near-homogenous phase with only occasional zonation, which indicates that the quartz in the veins have crystallized in one period only. This also indicates that all of the fluid inclusions in the samples are contemporaneous. Four different phases of fluid inclusions were found.Evaluating the results is not an easy process, but the conclusion is that there probably have not been any findings of Molybdenum in the quartz veins that have been examined.