Etched quartz crystal has abrasions on the outer areas of the crystal that look like hieroglyphics or writing of some sort.

To me, Etched crystals (or the etching on crystals) is symbolic in that it looks like writing. (For example, in the case of Lightning Strike, it looks like a lightning bolt zigzagging across.)

I feel that the best way to work with Etched quartz crystal depends on the particular shape the etching takes (refer to Sigil crystals).