Crystals are one of the first things anyone gets into when they start getting into new age stuff. They are also ridiculously to easy to source. There is one for just about everything but the question is how and why they work.
Einstein believed everything in the universe had a vibration on a molecular level which is correct. They can prove that bit with science The molecules viberate around an equilibrium point kinda like the reed in a saxaphone. How does that relate to crystals? Well the idea is that the crystals work on that minute viberational level. The assumption is that they can bring your body to the same level as that of the crystal thus effecting your body. I’ve also heard the argument that crystals structures are set and therefore hold at that viberation. Is it hard science? Heck no. The science facts are right but linking them together in this way is a bit of a stretch.
There has done studies into crystals though that says yes, there is a placebo effect and it does work. So as long as you want them to work, real or not, there is a measurable effect.
Does this mean that you should not buy crystals? Heck no! I love me a good crystal just like I am a fan of evidence based science. They are pretty and having them around makes me feel good (hello placebo effect). I think they could also serve as a good reminder or prompt for focusing on certain element. Want to love yourself more? Slip a piece of rose quartz in your pocket to remind you. There is no harm in that whatsoever. Would I try and heal a serious medical condition with crystals? No. That’s better left for someone with a whole degree and letters after their name. Otherwise go nuts and have all the shiny things you want.