Rare earth metals, used in a variety of scientific and industrial processes, are due for a sharp upswing in price due to supply concerns, says legendary commodities investor Jim Rogers. China controls more than 97 percent of the world's rare earth metals and has said it will crack down on illegal mining as well as curb exports.

"The future of rare earth is great. What is happening is the prices are going through the roof because the Chinese do control the supply, but it is pure simple capitalistic economics now,” Rogers tells India’s business television channel ET Now.

The time to buy rare earth metals — used in green energy and high-tech components such as wind turbines, fiber-optic cables, cell phones and flat-screen monitors — is now, as prices will come down when new mines eventually open.

"So it’s all going to bring a new supply and eventually the price of rare earth will come down again. But in the mean time until the new mines can come on stream, somebody is going to make a lot of money."

Rare earth elements like dysprosium, terbium and europium come mainly from southern China.

According to a United States Energy Department report, dysprosium, crucial for clean energy products has risen to $132 a pound today from $6.50 a pound in 2003.

"We do believe that this source of supply is diminishing, and there is some evidence leakage over the border into Vietnam is diminishing," Judith Chegwidden, a managing director specializing in rare earths at Roskill Consulting Group in London, tells the New York Times.