I am not sure how deep Martha mine is because every day at around 12:00 the miners use dynamite to expose more rock at the bottem of the pit so its depth changes every day.
You have to mine pretty deep for diamonds (if that's what you're asking)
In 1878 John McCombie and Butt Lee discovered gold at Martha hill and began the Mine. Waihi was then built around the mine to house the workers etc...
Deep Mine
in afraka
80 to 100 foot deep
Martha Emmons has written: 'Deep like the rivers' -- subject(s): African Americans, Folklore
2 kilometres
7,000,000 feet deep2133.6 kilometre deep
Nodules are hard to mine because they are found in very deep water
At the bottom of a deep mine.
The type of mine is called a strip mine.
The Homestake Mine in South Dakota reached depths of over 8,000 feet (2,438 meters) during its operation. It was the largest and deepest gold mine in North America before closing in 2002.