underground mining is done when the rocks, minerals of gemstones are too far

underground to get out with surface mining some kinds of underground mining are

Borehole Mining

Drift Mining

Hard Rock Mining

Shaft Mining

Slope Mining

hard rock mining, underground mining

• Rock drills
• Explosives
• Shovels
• Conveyer belt
• Elevators
• Ventilation fans
• etc.

It had hydraulic mining and hard-rock mining

Placer mining was largely replaced by hydraulic mining and hard rock mining methods. Hydraulic mining used high-pressure water jets to extract minerals, while hard rock mining involved digging tunnels and shafts to access mineral deposits underground. These methods were more efficient and able to extract minerals from deeper beneath the surface.