I thought it would be interesting to pass on some of why findings regarding magnesium oxychloride cement, patented in 1800's as Sorel's cement. It is important because it may easily be mistaken as scagliola or stucco - but is an entirely different material chemically. It is interesting that it is a totally natural cement, based on dried up ancient oceans for its two components

The modern variation is 10,000 to 12,000 psi compressive strength - thats up around Moh 2 on another scale - like grantite - no gypsums or cements can approach that level without a lot of special modifications. Plain portland cement is about 2,000 psi.

It is completely fireproof - up to 2300 degrees fahrenheit and can withstand a tensile shock. It is simply the very best flooring and wall material available. It resists both acids and solvents.

Here is a link explaining some of its historic use in the los angeles area:
http://homeandhearth.keenesentinel.com/design.htm#2

Restorers should also be aware that early practitioners added cheap, asbestos fiber as a bulking filler. Another filler is wood flour, because unlike lime or cement, this material is not alkaline and can use organic fillers - like wood, straw or hemp. It shrinks very slightly, so a lot of hard sand filler is not needed. It cures in four hours and does not require continuous wet.

It has fallen out of favour because it is expensive compared to standard concrete and gypsum. But there is simply no substitute for scultped and or highly polished finishes.