Indicator minerals are minerals formed at great depths and moved to the surface by the same deep-source rocks as diamonds. Which description best matches their role?

Indicator minerals are minerals formed at great depths and moved to the surface by the same deep-source rocks as diamonds. Which description best matches their role?

• A. Minerals formed at depth and moved to the surface by kimberlites or lamproites
• B. Minerals formed at the surface and unrelated to diamonds
• C. Minerals only found in ocean environments
• D. Minerals that indicate color zoning in diamonds

Answer: (A)

Indicator minerals reveal what's happening deep in the mantle by forming there and then being carried to the surface by deep-source magmas like kimberlites or lamproites. These rocks originate far down and bring with them mantle-derived minerals as they rise explosively to form diamond-bearing pipes. Because diamonds form in the same deep environment and travel with the same magmas, finding these minerals at the surface signals a potential diamond system underground. The other descriptions don’t fit this relationship: minerals formed at the surface aren’t tied to deep-source diamonds, oceans aren’t the realm where these deep-origin minerals travel, and minerals that indicate color zoning in diamonds describe a property of the diamond itself rather than a deep-source indicator mineral carried by kimberlites or lamproites.

Indicator minerals reveal what's happening deep in the mantle by forming there and then being carried to the surface by deep-source magmas like kimberlites or lamproites. These rocks originate far down and bring with them mantle-derived minerals as they rise explosively to form diamond-bearing pipes. Because diamonds form in the same deep environment and travel with the same magmas, finding these minerals at the surface signals a potential diamond system underground. The other descriptions don’t fit this relationship: minerals formed at the surface aren’t tied to deep-source diamonds, oceans aren’t the realm where these deep-origin minerals travel, and minerals that indicate color zoning in diamonds describe a property of the diamond itself rather than a deep-source indicator mineral carried by kimberlites or lamproites.