Potency of Alluvial Mineral of Luk Ulo River with XRD and AAS in Kebakalan Village Kebumen

: Based on petrographic data, XRD, and fluid inclusions, it was interpreted that the quartz veins associated with low sulfide in Karangsambung area underwent 2 stages of system change from mesothermal system to epithermal system. This showed the potential mineral contained in the material, especially in the Luk Ulo River where there were alluvial deposits. To determine the mineral and material composition contained in alluvial material in Luk Ulo River, Kebakalan Village, AAS and XRD were used. This research was limited only to testing Au, Ag, and Cu from 2 samples, namely sample A for sand and sample B for rock. XRD results on samples A and B showed that quartz (SiO 2 ) had the highest percentage (30-50%) compared to other minerals. While the results of the AAS tests showed that the highest Au and Ag contents were in sample B and Cu in sample A with total of 19.30 g/ton Au, 8.67 g/ton Ag, and 62.88 g/ton Cu. Meanwhile, the lowest total Au and Ag were in sample A and Cu was in sample B which amounted to Au 11.32 g/ton, Ag 2.77 g/ton, and Cu 34.86 g/ton.