There�s a growing body of evidence that indicates the ancients built pyramids, temples, statues and other objects out of manmade geopolymer cast stone as documented by Professor Joseph Davidovits and other researchers at the Geopolymer Institute. I�ve been investigating the potential of using geopolymer cast stone as a low cost, durable fill material in earthbag houses and reporting my findings on our Earthbag Building Blog.

The basic process is quite simple. The ancients used limestone, kaolin clay, sodium carbonate, lime and water to make cast stone in situ. (See the excellent video in the above link.) Now the process is even easier because the basic ingredients (sodium carbonate and lime) can be purchased off the shelf and mixed with limestone and water. Scientists also have shown how all the necessary materials can be obtained from fly ash, slag from iron ore processing, and mining tailings to produce geopolymer cement from 100% waste materials.

The end product is actual stone, not just something �hard as rock�. This geopolymer Stone Dome would be fire and rot proof, bulletproof, totally waterproof obviously, and could possibly last thousands of years. Not much else can compare to this. Even modern concrete falls way short, because it�s brittle, too expensive, shrinks and cracks as it dries, is vulnerable to acidic reactions and freeze/thaw cycles, is a major cause of global climate change, and so on.

Specifications: 133 sq. ft. interior main dome, 38 sq. ft. loft, 78 sq. ft. small dome, plus 8 sq. ft. vault, 257 sq. ft. interior total, Footprint: 16? x 29? plus benches
Description: Like other tiny houses, the Stone Dome provides just the basics in a compact space. It is intended as a starter home for those with little or no building experience and very little money. This design joins a 13? interior diameter main dome with loft and a 10? interior diameter small dome, with a vaulted passageway.

More details are in my original Stone Dome proposal that was posted a few weeks ago: http://earthbagbuilding.wordpress.com/2011/04/30/earthbag-stone-dome/