Which rock is most closely linked to transporting diamonds to the surface through volcanic eruptions?

• A. Kimberlite
• B. Granite
• C. Limestone
• D. Basalt

Answer: (A)

Diamonds form deep in the mantle under high pressure, and the rocks that bring them to the surface do so quickly and violently. Kimberlite is the ultramafic volcanic rock that does this most effectively. It ascends from mantle depths as a volatile-rich, gas-rich magma and erupts in steep, carrot-shaped pipes called diatremes. This rapid ascent captures diamonds in the magma and carries them upward to shallower crustal levels, preserving them for surface exposure. That combination of deep mantle origin and fast transport is what links diamonds so closely to kimberlite.

In contrast, granite is formed deep in the crust as a plutonic rock, limestone is sedimentary, and basalt, while volcanic, usually carries surface lava flows and does not serve as the primary carrier for mantle-derived diamonds to the surface.