Hard disagree: they exhibit 4 perfect octahedral cleavage planes in addition to their adamantine lustre, diamond is one of the most useful materials in existence, and their petrological origins speak to incredibly interesting conditions of formation! In fact, a mineral inclusion within a diamond gave us our first solid evidence of the existence of water at equilibrium with mantle rock at depth on Earth, which was previously largely discounted.

But yeah, fuck De Beers.

It’s also good for (at least some?) neurological people.

I would like to preface that I am not saying this to be judgemental and I'm not implying that anyone was hurt by it, but,

I'm not sure if you used "neurological" instead of "neurotypical" on purpose...? Because literally every creature with a brain is neurological.

And while I definitely used "neurodiverse" instead of "neurodivergent" on purpose because it feels nicer, implying that the opposite term is "neurological" might sound to some as though you are implying that neurodivergent/aneurotypical people have no neurological framework and I hesitate to jump to the conclusion that that's actually what you meant.

best I can do is two marbles and a stick