Secondary diamond deposits are found in which settings?

• A. Found inside lamproite and kimberlite pipes
• B. Found away from source
• C. Found in alluvial and marine settings
• D. Rivers & streams

Answer: (C)

Secondary diamond deposits are placer-like accumulations that form when diamonds are eroded from their primary source rocks and transported by water to new locations. These diamonds settle out in environments where sediment is deposited by moving water or along coastlines, specifically in alluvial and marine settings. That broad category includes river gravels and beach or offshore placers, where diamonds can accumulate after transport. The other options point to primary deposits hidden in pipes formed by kimberlite or lamproite, or are too vague or narrow: rivers and streams are a subset of alluvial settings, while “found away from source” doesn’t specify the depositional environment.