That is called deep mining.
Mining
hard rock mining, underground mining
Focus
focus UwU
focus UwU
focus UwU
A deep crack in the earth's surface is called a fault.
Diamonds are formed deep within the earth's mantle.
Yes, diamond is a raw material and is located deep within the earth's mantel.
Magma if it's beneath the crust, lava if it's above the crust
Fermium is an artificial element.
subduction
the deep crack in the earth's surface is the rift