What testing targets the detection of microscopic diamonds in sand or sediment?

• A. Open pit
• B. Drift
• C. Shaft
• D. Micro diamond testing

Answer: (D)

Micro diamond testing focuses on detecting diamonds that are too small to see with the naked eye in sand or sediment. In exploration, this means collecting sediment samples from placer areas, concentrating the heavy minerals, removing the organic and silicate matrix, and then inspecting the residues under a microscope (often with mineral separation or spectroscopy support) to identify diamond grains. This targeted approach is what lets geologists confirm the presence of diamonds in a sand or sediment sample without relying on finding large, visible stones.

The other options refer to mining methods—ways of extracting ore from rock rather than methods for testing for diamonds in sediment. Open pit, drift, and shaft describe how material is accessed and moved, not how you detect microscopic diamonds in the ground.