Scientists have found holes filled with minerals that indicate fluid-filled pores exist many tens of kilometers below Earth’s surface. But no, The Core fans, you still can’t get amethyst-laden geodes in the mantle.
eclogites
Are Diamonds Ubiquitous Beneath Old Stable Continents?
Although rare at the Earth’s surface, diamonds may be commonplace at depths of 120 to 150 kilometers below the surface within the lithosphere of old continents.
Variable Mantle Lies Below Ancient Pieces of Earth's Crust
Underneath old and stable pieces of Earth's crust in North America, the mantle's uppermost portion contains multiple layers that change the velocities of seismic waves.
New Insights into the Formation of Old Norwegian Mountains
Researchers look to minerals in rocks from Norway's Western Gneiss Region to determine when the mountain-making period came to a close in the region.