Fascinating! The New Jerusalem's Walls...

"The wall of the city was built on foundation stones inlaid with twelve precious stones the first was jasper, the second sapphire, the third agate, the fourth emerald, the fifth onyx, the sixth carnelian, the seventh chrysolite, the eighth beryl, the ninth topaz, the tenth chrysoprase, the eleventh jacinth, the twelfth amethyst." (Revelation 21:19)

In the past century, it has been discovered that gems can be classified as either anisotropic or isotropic, and only recently have scientists discovered cross polarized light, which can be used to identify whether a gem is anisotropic or isotropic. When viewed in crossed-polarised light (similar to “pure” light), anisotropic stones produce a colourful array- reflecting all the colours of the rainbow, whereas isotropic stones lose all of their colour and appear black.

It's interesting that, in Revelation chapter 21, there are 12 gems mentioned to be inlaid for decoration of the New Jerusalem