Approximately how far beneath the Earth's surface do diamonds form?

Approximately how far beneath the Earth's surface do diamonds form?

• A. 10 to 20 miles
• B. 60 to 80 miles
• C. 90 to 140 miles
• D. 200 to 260 miles

Answer: (C)

Diamonds form deep in the Earth’s mantle where pressures and temperatures are extremely high. The stable diamond-forming zone is commonly cited around 140–190 kilometers below the surface, which is about 87–118 miles. The range of roughly ninety to a hundred forty miles aligns with this mantle depth, making it the best approximate answer. Shallower depths (around ten to twenty miles or sixty to eighty miles) don’t reach the necessary high-pressure conditions, while much deeper depths (around two hundred to two hundred sixty miles) go beyond the typical primary formation zone. So, the best match is roughly ninety to a hundred forty miles beneath the surface.

Diamonds form deep in the Earth’s mantle where pressures and temperatures are extremely high. The stable diamond-forming zone is commonly cited around 140–190 kilometers below the surface, which is about 87–118 miles. The range of roughly ninety to a hundred forty miles aligns with this mantle depth, making it the best approximate answer. Shallower depths (around ten to twenty miles or sixty to eighty miles) don’t reach the necessary high-pressure conditions, while much deeper depths (around two hundred to two hundred sixty miles) go beyond the typical primary formation zone. So, the best match is roughly ninety to a hundred forty miles beneath the surface.