My previous roommates (a couple) were both big into xanax and crystals. They'd go on walks around the town, f'd up on scrips, and pick up rocks, bring them home and gush at me about what they found 'look at this ruby!" They'd proclaim (it was just a shard of broken beer bottle, I kid you not). By the end, the side of our house had accumulated a several hundred pound collection of (totally mundane and worthless) rocks. Their plan was to crack these rocks open by throwing them at the (concrete) ground, hoping to find crystals inside. In my opinion the benzos infantilized them, because they were not like that when they moved in, it was a downward spiral of a transition over two years.
This wasn't even thier worst quality. But I will always remember thier 'crystal' hobby.
Thinking of that made me realize that I would rather date someone on crystal meth than someone on crystals.