These environmentally friendly bricks are made with a new manufacturing process that eliminates the need for firing. As a result, they require 85 percent less energy than clay bricks and emit 85 percent less CO2, the company claims. In addition, the company uses 40 percent post-industrial recycled flyash material as the binder. The bricks come in eight colors and two sizes. CalStar Products, 877.700.9501; http://www.calstarproducts.com/.