What exactly are "diamond-tipped" drill bits?

[Magiver]

@Chronos

While we’re at it, carbide tools are made of silicon carbide, a material very similar to diamond (basically, diamond with half the carbon atoms replaced by silicon). It’s not quite as hard as diamond, but it’s still pretty hard, and much cheaper and easier to make tools out of.

And when drilling masonry it is more useful to use a hammer drill than to have a diamond tipped drill. If diamond tipped drills are expensive then the money should be invested in the drill for any serious work.