I’m pretty sure that lab-grown precious gems could and should be used for some sort of witchcraft fuckery purposes. This is one of those “I have no way to even begin to rationalise this, but I feel like it should be logical” sort of things. Like there’s some inherent elemental safety buffers in natural gems and crystals that manufactured ones wouldn’t have, so you could do some absolutely nuclear wizard shit with them. Like how being born through c-section or having a trans man father would technically exclude you from “no man of woman born” in a prophesy.