A cache of rare Gold Rush-era coins, unearthed in California by a couple as they walked their dog, may be the most valuable haul of treasure ever found in the US.
A currency firm representing the couple said on Tuesday that the find is worth more than US$10 million (S$12.7million).
The 1,400 gold coins, dating to the mid- to late 1800s and still in nearly mint condition, were discovered buried in eight decaying metal cans on the couple's land last April, said coin expert David McCarthy of currency firm Kagin's.
"We've seen shipwrecks in the past where thousands of high-grade gold coins were found, but buried treasure of this sort is unheard of," Mr McCarthy told Reuters.
"I've never seen this face value in North America and you never see coins in the condition we have here."
Kagin's has declined to identify the couple. According to the firm, they want to remain anonymous for fear of treasure hunters descending on their property in northern California's so-called Gold Country, named after the state's 1849 Gold Rush.
The couple came across a rusty metal can sticking out of the ground and dug it out. After finding gold coins inside, they searched further and found the rest of the cache.
What is unclear is who hid the gold pieces, which were minted between 1847 and 1894, in various 19th century metal cans.
Mr McCarthy said it was curious that the containers were discovered scattered across one section of the property at different depths, suggesting that they were not all put there at the same time.
He added that the couple wisely refrained from cleaning the coins themselves and brought a sampling of them to him in small bags.
His company took the cache to an independent coin-grading service, which found that it was comprised of nearly 1,400 US$20 gold pieces, 50 US$10 gold pieces and four US$5 gold pieces.
One of the coins, a so-called 1866-S No Motto Double Eagle, is said to be valued at US$1 million on its own.
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