Linked from
The 10 pages that link to Mantle xenolith, each with the reason it gives.
DiamondRelated: Some contain diamonds that provide evidence about conditions deep within Earth.
OlivineRelated: Olivine in these fragments reveals the composition and history of the upper mantle.
CratonRelated: Xenoliths provide direct samples of the mantle beneath cratons.
KimberliteRelated: Kimberlite can transport mantle fragments alongside diamonds.