Know all about Variolite and Oil shale properties here. All properties of rocks are important as they define the type of rock and its application. Variolite belongs to Igneous Rocks while Oil shale belongs to Sedimentary Rocks.Texture of Variolite is Glassy, Massive, Porphyritic, Scoriaceous, Vesicular whereas that of Oil shale is Splintery. Variolite appears Dull and Soft and Oil shale appears Muddy. The luster of Variolite is not available while that of Oil shale is dull. Variolite is available in black, brown, light to dark grey colors whereas Oil shale is available in black, brown, buff, green, grey, red, yellow colors. The commercial uses of Variolite are cemetery markers, creating artwork and that of Oil shale are an oil and gas reservoir.