There are two kinds of sandstone block in India.
Sedimentary sandstone which has natural cleft in the block. The clefts are opened manually using chisel and hammer, the finished is riven face. The blocks are first made into slabs of 25-40mm, and then these slabs of stone are cut into size by hand made. The entire process is manual, and no machines are involved. A recent development in this category of stone has been to calibrate the stone to 22mm, some people like to tumble it. The quarry area for sedimentary sandstone is in the region of Kota, Rajasthan.
