Finding diamonds hidden deep in the Earth would be a lot easier if there was a big neon arrow pointing at the places where they're buried. Now, a geologist working in Liberia has discovered nature's equivalent of such a sign. It's a rare plant identified as Pandanus candelabrum that seems to grow only on top of volcanic columns of kimberlite, a material that sometimes contains diamonds.
Kimberlite pipes are columns of volcanic rock that formed from ancient eruptions. On their journey from deep inside the Earth's mantle, they sometimes carry diamonds up with them. The soil above these pipes is rich in magnesium, potassium and phosphorus -- components the Pandanus candelabrum plant seems to love. In fact, it's theorized that the only place the plant grows is above columns of kimberlite. So find the plant, potentially find a kimberlite tube. Find a tube and you just might find some diamonds.
The man who uncovered the plant's kimberlite-loving nature is Stephen Haggerty, a researcher at Florida International University in Miami. His discovery appears in the current issue of the journal Economic Geology.
Haggerty, who's also the chief exploration officer of Youssef Diamond Mining Company (which owns mining concessions in Liberia), told Science magazine that while the plant is a good indicator of a kimberlite pipe, it's good to follow a rule of sixes to determine which pipes will hold diamonds. "Of the more than 6,000 known kimberlite pipes in the world, about 600 contain diamonds," the Science article said. "Of these, only about 60 are rich enough in quality diamonds to be worth mining."
So finding a Pandanus candelabrum isn't a sure sign you'll strike it rich, but still, having a plant do the initial scouting work for prospectors could be a huge time and money saver. With its spiky leaves, above-ground stilt-like roots similar to mangrove trees, and tendency to grow to heights of about 32 feet (10 meters), the plant's easy to spot -- even from the air.
While scientists have previously used termite mounds to pinpoint deposits of kimberlite in the soil, this is the first time a plant that does the same thing has been identified, according to the abstract accompanying the research. "This could dramatically change the exploration dynamics for diamonds in West Africa, as geobotanical mapping and sampling is cost-effective in tough terrain," it says.
About the discovery, Steven Shirey, a geologist specializing in diamond research at the Carnegie Institution for Science in Washington, D.C., told Science that prospectors are going to "jump on it like crazy."