Milton Friedman

The price of diamonds can vary greatly depending on size, cut, color, and other factors, including whether they have a history. But because of the rarity of blue boron diamonds, they often fetch more money than gems of similar quality.

But if, on the other hand, we should be justified in rejecting it, if there testified on oath, then, supposing our rules of evidence to be sound, we may be excused if we hesitate elsewhere to give it credence.