Some background material (for those interested):
Sand, rarer than one thinks
https://na.unep.net/geas/archive/pdfs/GEAS_Mar2014_Sand_Mining.pdf
Book on sand written by a geologist:
https://www.amazon.com/dp/0520265971/?tag=thneyo0f-20
Sand, rarer than one thinks
https://na.unep.net/geas/archive/pdfs/GEAS_Mar2014_Sand_Mining.pdf
Book on sand written by a geologist:
https://www.amazon.com/dp/0520265971/?tag=thneyo0f-20