Diamond (in conglomerate)

Diamonds hitch a ride to the surface in rare magmas called kimberlite and lamproite, which form by partial melting of the upper mantle. Gas expansion propels these magmas upward at rates of 10-30 kph (6-19 mph), giving their diamond passengers a commute time of just 4-15 hours from mantle to surface! At the surface water can transport the diamonds and other particles away from the point of eruption, leaving the diamond embedded in sedimentary rocks, like this conglomerate.

Group: Native Elements
Catalog Number: 140603
Locality: Minas Gerais , Brazil