So I acquired this nice chunk of quartz recently. Lots of small crystals, some pyrite bits, and an intriguing shape. It has tinges of delicate green and very faint purple, with a darker green on the bottom shading into the white. Difficult to see in a photo, but here it is, modeling this bracelet:
Quartz, right?
Or so I thought.
I took it outside to get a better look, and was startled to find that nearly the whole thing was tinted with purple! Maybe a few light hints of green. The rock looked completely different!
I went back inside.
Green.
Outside.
Purple.
What the heck?
It’s not unknown for certain minerals to look different under different kinds of light, but this is the most obvious case of it I’ve seen outside a rocks and minerals study lab.
Looking it up online, I found Alexandrite, which does show green under artificial light and turns purplish under natural light – looks like my mystery is solved!
Wait… not so fast there, either.
Alexandrite is actually green under natural light but goes purple under artificial light, which is backwards from my mystery rock. So what exactly do I have anyway? Do I have Etirdnaxela?
After even more research, I was finally able to solve the mystery. It’s fluorite! Two things tell me that. One, the color change works the right way. And two, there’s a great big cubic structure in the rock – that’s what the big corner in the rock is!
So I tested it with a UV flashlight – and it fluoresced bright pinkish purple! That clinched it. The thing is fluorite!