Actually, unless I'm mistaken, for Roland Garros, thay actually bust up and grind clay pottery into the clay dirt that we see on T.V. I know that not all clay courts go thru the same process, or even use the same material.
one last thing that I've been wondering. What are the lines on a clay court. Like are they painted, though I doubt it because they would have to re-paint them ever 2 min. Or are they like a plastic tape or something???? just wondering
I think describing them as white shingles might be inaccurate. It's more like a heavy piece of white plastic tape, with aluminum nails to keep it down. Some places use a line striper, which puts down chalk.