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Sandstone is easy. If you rub it with your hand or with another rock the particles of sand will come off depending how friable it is. Sandstone in general has a gritty feeling to it.

Lydite is mostly quartz. it comes from those tiny organisms in the sea that die and their casts are silica. Radiolarians as I recall. It's kind of like Chert and sedimentary.

They also use slate...