An inter-laboratory comparison study was carried out between twelve participating laboratories inside and outside Jordan using eleven different analytical methods. Meanwhile, the oil shale samples sent to each participant laboratory and asked for analysis using the available analytical technique/s. The oil shale sample was characterized for the following parameters: oil content, total carbon, organic carbon, ash, calorific value, moisture, loss on ignition, minerals, oxides, major and minor elements in twelve participating laboratories inside and outside Jordan using eleven different analytical methods. Meanwhile, the oil shale samples sent to each participant laboratory and asked for analysis using the available analytical technique/s. The results collected from participant laboratories were analyzed statistically after outlying the extreme values applying Q-test and evaluated applying z scores for satisfying the result of each participant.

Keywords: SJL-1; Inter-laboratory comparison; Oil shale; El-lujjon