Lightning Does Not De-Rust Raw Copper Blocks

When lightning strikes raw copper, nothing happens.

What I expected to happen:

I expected lightning to turn raw copper blocks into regular copper, since raw copper blocks are simply a block of copper ore, and ore is just rock made out of rusted copper.  Since raw copper is essentially the same as rusted copper, is should be de-rusted by lightning.

What actually happened:

The raw copper was unaffected, although it did get set on fire as usual.

Steps to reproduce:

1. Place some raw copper blocks on the ground.

2. Use the command /summon lightning bolt ~ ~ ~

The raw copper will remain the same.