My sister's quartz cluster caused a kitchen disaster
She left it on the counter, and my nephew thought it was a giant sugar crystal. He tried to lick it and knocked over a whole jar of flour. What's the funniest way a relative has misunderstood a geological specimen?
Reading about your nephew and the quartz cluster made me laugh. I always assumed rocks were pretty clear cut, you know, just stones. My dad once brought home a piece of obsidian and my brother was convinced it was a weird kind of candy because it was so shiny. He actually tried to bite it and chipped a tooth. That was the day I learned people can see geology in totally wrong ways. Your sister's experience sounds just as chaotic.
After @alicehernandez talked about that obsidian candy thing, I remembered my grandma's petrified wood paperweight. My uncle visited and thought it was a weird burnt loaf of bread, like from some artisanal bakery. He actually picked it up and tried to sniff it, then dropped it right on the glass coffee table. Cracks EVERYWHERE and we spent the afternoon picking tiny glass bits out of the carpet. Rocks just invite this kind of weird mess.