First of all, sarcasm is the first reaction we get from people who are insecure with their facts or their ability to refute a significant rebuttal. It is a sign of weakness to attack the commenter rather than to refute the statements made in the rebuttal.

I never denied that are criminal enterprises involved in the sand trade, nor that it is a significant problem where it occurs. As it happens, an acquaintance of mine owns a sandpit in Jamaica which produces the highest quality construction sand in the world, according to him. He’s selling out because his operations have become targets for the criminal element in the area, so I have direct knowledge of this problem.

Furthermore, I am well aware of the different grades and characteristics of various sands, as I have been all my life. During my training in chemical engineering, I took a class in foundry operations, where we learned that the only sand that could be used in casting metals was the green sand that comes from the Mississippi delta. So, we did an experiment. We went to Coney Island, gathered some sand, washed it, sifted it and used it to make a casting. Worked perfectly.

What I said was that this is a false issue because there is no shortage of either silicon dioxide or calcium carbonate in the world, which is an undeniable scientific fact, not an opinion. I also pointed out that sand can be manufactured as you did.