'Stunning' cache of gold coins found in Kentucky cornfield

A trove of more than 700 gold coins dating back to the US Civil War found buried in a cornfield in the state of Kentucky is being put up for sale and is expected to reap millions.

The "Great Kentucky Hoard" was discovered on a farm in the Bluegrass State earlier this year, according to the firm which graded the coins and the company selling them.

The exact location of the find and the identity of the man who found the coins have not been revealed.

In a video posted on GovMint.com, which is selling the hoard, the man is seen digging up the coins in the dirt and heard saying "this is the most insane thing ever."

GovMint.com said the coins were dated between 1840 and 1863 and include $1 Gold Indians, $10 Gold Libertys and $20 Gold Libertys.

Among them are 18 extremely rare $20 Gold Libertys minted in 1863 in Philadelphia which GovMint.com said fetch six-figure sums from collectors.

"The importance of this discovery cannot be overstated," said Jeff Garrett, a rare coin dealer who was contacted by the anonymous finder several months ago.

"The stunning number of over 700 gold dollars represents a virtual time capsule of Civil War-era coinage," Garrett said in a statement.

Kentucky adopted a neutral stance during the 1861-1865 Civil War between the slave-holding South and the North but was nevertheless drawn into the bloody conflict.

"The Great Kentucky Hoard may have been a result of this conflict, with the coins lost for over 150 years," said Numismatic Guaranty Company, which certified the coins.