Know all about Siltstone and Tephrite properties here. All properties of rocks are important as they define the type of rock and its application. Siltstone belongs to Sedimentary Rocks while Tephrite belongs to Igneous Rocks.Texture of Siltstone is Clastic whereas that of Tephrite is Aphanitic to Porphyritic. Siltstone appears Rough and Tephrite appears Vesicular. The luster of Siltstone is dull while that of Tephrite is subvitreous to dull. Siltstone is available in brown, red, reddish brown colors whereas Tephrite is available in black, brown, colourless, green, grey, white colors. The commercial uses of Siltstone are raw material for the manufacture of mortar, soil conditioner and that of Tephrite are production of lime, soil conditioner.