"Our consumption of sand is outpacing our understanding of the economics and environmental impacts of extracting, transporting, and consuming it, finds research published last Thursday in the journal Science. Out of the complexity of the global sand trade has emerged something of a butterfly effect, in which an economic decision in one place can wreak social and environmental havoc on the other side of the world. "

https://www.csmonitor.com/Environment/2017/0914/It-s-a-small-world-after-all-say-scientists-warning-of-sand-scarcity

An instinctive approach to the surrounding environment has led me away from using sand for construction. I find that, for all practical purposes, anything you can do with sand can be done equally well with paper pulp mixed with latex paint. It is lighter and has better thermal qualities than sand. But sand has advantages through speed of application and indisputable fire retardancy. (BTW, densely packed paper pulp that is then dried allows no air circulation within its mass, and is therefore fire retardant.)