There is one type that does, but I still can't name it. Can anyone help?

The brilliantly-named Ogre-Faced Spider carries a net that it pushes down on to its prey to snare them.

When an ant walks near the hole the quartz crystals transmit the vibrations of the ants footsteps down the line. The spider then jumps out for its meal. Amazing! Now how the heck do we get to that? I usually just think to myself about how long arachnids have been around and how short their generations are but can't imagine exactly how this could arise.

Spiders are all adept at detecting vibrations - many attach a special string of silk to their web, then lie in wait in a safe place, waiting to feel the vibration of something on the web travelling down the string. Male spiders also attract females for mating by strumming the web in a specific manner.

Assuming that the forebears of the spider you mention were already 'set up' for vibration detection, it becomes easier to envisage a scenario whereby, in spiders living in an environment rich in quartz crystals, those crystals become involved in the prey detection process. If a spider happens to behave in a way that leads it to leave web strands around its burrow, and this causes it to detect more prey, than that tendency will be passed on and enhanced via EtNS.