Which statement about kimberlite pipes and diamond content is accurate?

Which statement about kimberlite pipes and diamond content is accurate?

• A. Most kimberlite pipes do not contain diamonds in profitable quantities
• B. Most kimberlite pipes are diamond-rich
• C. Diamonds are formed in granite pipes
• D. Pipes are always barren of diamonds

Answer: (A)

Diamonds in kimberlite pipes are not uniformly distributed, and profitability depends on the amount and quality of diamonds present. Most pipes carry too few diamonds or too low a grade to mine profitably, so they aren’t economically viable sources. That makes the statement that most kimberlite pipes do not contain diamonds in profitable quantities the correct one. Diamonds form deep in the mantle under high pressure and are brought to the surface by kimberlite magma; they are not formed in granite pipes. While some pipes do contain diamonds, not all are diamond-bearing, and many are effectively barren from an economic standpoint.

Diamonds in kimberlite pipes are not uniformly distributed, and profitability depends on the amount and quality of diamonds present. Most pipes carry too few diamonds or too low a grade to mine profitably, so they aren’t economically viable sources. That makes the statement that most kimberlite pipes do not contain diamonds in profitable quantities the correct one. Diamonds form deep in the mantle under high pressure and are brought to the surface by kimberlite magma; they are not formed in granite pipes. While some pipes do contain diamonds, not all are diamond-bearing, and many are effectively barren from an economic standpoint.