A plant that leads to diamond deposits

New York, May 11
A geologist has found a rare African plant that prefers to grow on diamond-bearing kimberlite rocks. The plant, identified as Pandanus candelabrum, is the first indicator species for diamond-bearing rocks, Stephen Haggerty, researcher at Florida International University in Miami, told Science magazine.

The thorny, palmlike plant in Liberia grows on top of kimberlite pipes -- columns of volcanic rock hundreds of metres across that extend deep into the Earth, left by ancient eruptions that exhumed diamonds from the mantle.

The findings suggest that diamond hunters in West Africa could have a simple, powerful way of finding diamond-rich deposits. Haggerty thinks the plant adapted to grow in the kimberlite-rich soil because it contains high levels of magnesium, potassium, and phosphorus.

Kimberlite pipes bring the gems to the surface in eruptions that sometimes rise faster than the speed of sound. The pipes are rare.

According to Haggerty, who also works as the chief exploration officer of Youssef Diamond Mining Company which has mining interests in Liberia, of the more than 6,000 known kimberlite pipes in the world, about 600 contain diamonds -- and of these, only about 60 are rich enough in quality diamonds to be worth mining,

"If researchers can learn to spot the plant via aerial survey, it could help countries in the area develop new diamond mines without having to fight their way through dense forests, " he said.

Haggerty, who has worked in Liberia off and on since the late 1970s, has in recent years focused his prospecting efforts in the northwest part of the country.

The findings were reported in the journal Economic Geology.