Why blue diamonds?
he diamonds in NDB’s battery have a beautiful blue hue,, they’re formed in Earth’s lower mantle, which is about 660 to 2 700 km below the surface. As such, you can only find blue diamonds in three mines in the entire world, which helps explain their hefty price tag: roughly $15 700 for a 0.3 carat light blue diamond, and $75 000 for a 0.25 carat dark blue diamond.
