You're looking at a "biomanufactured brick," the creation of American architecture professor Ginger Krieg Dosier. The brick, which is made by mixing sand with a non-toxic bacteria, requires no heat for the hardening process, and could bring this staple of basic architecture to areas of the world lacking modern infrastructure, all while dramatically reducing CO2 emissions worldwide.
According to Bustler:
There are over 1.3 trillion bricks manufactured each year worldwide, and over 10% are made by hand in coal-fired ovens. On average, the baking process emits 1.4 pounds of carbon per brick - more than the world's entire aviation fleet. In countries like India and China, outdated coal-fired brick kilns consume more energy, emit more carbon, and produce great quantities of particulate air pollution. Dosier's process replaces baking with simple mixing, and because it is low-tech (apart from the production of the bacterial activate), can be done onsite in localities without modern infrastructure. The process uses no heat at all: mixing sand and non-pathogenic bacteria (sporosar) and putting the mixture into molds. The bacteria induce calcite precipitation in the sand and yield bricks with sandstone-like properties. If biomanufactured bricks replaced each new brick on the planet, it would save nearly 800 million tons of CO2 annually.
Dosier, who was trained as an architect, but studied microbiology, geology, and materials science in her spare time, was awarded the prestigious Metropolis Next Generation Design Prize for her work, which the judges felt best encapsulated the theme for that year's competition, which was "One Design Fix For the Future."
You can find more information, along with images of Dosier's ecobrick experiments, at bustler