Carat clue? African plant points to diamonds beneath ground, scientist says

Pandanus candelabrum at the Cascades de Banfora in Burkina Faso. (Image from Wikipedia by Marco Schmidt)
Diamond prospectors in West Africa finally have a clue where to look for the ‘girl’s best friend’. A US researcher believes that one particular plant could be “an unusual botanical indicator” which grows where there may be diamonds beneath the soil.

Liberia, a major source of ‘blood diamonds’, is home to the thorny plant whose name sounds like an incantation: pandanus candelabrum.

Florida International University researcher Stephen Haggerty claims that the plant grows over rock that may be hiding diamonds. The researcher wrote in the June-July issue of Economic Geology paper that following several years of exploration in northwestern Liberia “an elusive diamond-bearing kimberlite pipe has finally been located.”

A man displays a rough diamond. (Reuters/Emmanuel Braun)

Kimberlite is an igneous rock with a reputation for containing diamonds oftentimes; kimberlite pipes are the key source of mined diamonds. Haggerty says that a “bonus” to the pipe location is that pandanus candelabrum is recognized “exclusively on the pipe and not in eluvium [deposit of soil, dust, etc., formed from the decomposition of rock and found in its place of origin] covering the adjacent kimberlite dikes.”

The plant tends to grow only on the kimberlite-derived soil (potassium, phosphorous and magnesium-high) which appears at the top of pipes of the igneous rock.

The researcher, who’s also the chief exploration officer of Youssef Diamond Mining Company, which owns mining concessions in Liberia, believes that his discovery could “dramatically change the exploration dynamics for diamonds in West Africa, as geobotanical mapping and sampling is cost-effective in tough terrain.”

A geologist specializing in diamond research at the Carnegie Institution for Science in Washington, DC, Steven Shirey, told Science that diamond-miners are going to “jump on it like crazy.”

Miners are aware that particular plants, like haumaniastrum katangense in Africa or pink flowers of lychnis alpina (found in the mountains where the soil also contains copper) can tip-off which rocks lie beneath. According to Haggerty, pandanus candelabrum is “the first plant to be described that has a marked affinity for kimberlite pipes.” While kimberlite pipes are found around the world, pandanus candelabrum is only found in West Africa.