I figured out funny idea.
When scientists found out Maldek, the lost planet, they named it Krypton.
Nof far from where I live a meteorit fell down a long time ago and when it hit, a lot of green crystals were created, or rather green glass, that is like no other on Earth.
We call it Vltavine, but it might be called kryptonite too?
...you know, those bookstores Luxor in my country also are funny fitting into the idea.