Although the Sahara desert used to be a green retreat for giraffes and hippos 5,000 years ago, it is now a giant, sometimes rolling landscape of sand. A lot of sand. In fact, roughly two thirds of Algeria is made up of sand, according to the authors of a study published in the Arabian Journal for Science and Engineering. And they believe it can be used to produce a sustainable building material for a limping construction industry. That’s right, they want to turn the dunes into bricks, and they already have a pretty good formula. Since Algeria possesses very little in the way of aggregate materials that can be used in the construction industry, researchers from the University of Kasdi Merbah and the Polytechnic School of Algiers developed a new kind of brick made with little more than water, sand sourced from their own backyard – so to speak – and a binder.