I had the privilage of viewing a rare geological sight over the weekend. In the centre of the Ramon Crater in the Negev is Ha-Minsara (the Carpenter shop or the Saw-Mill) a hill covered in blocks of shaped black & rusty looking sandstone , liked wooden planks in a Saw-Mill. Unlike other rocks in the crater the strangly shaped rocks are made of sand."This is the only place in the world you see prisms made of heated sand that turned into liquid. In cooling, the molten mass naturally formed rectangular and hexagonal prisms, losing no space in the middle."
A must for all.