The Rutz Clovis point, a Palaeolithic projectile head, hammered for $276,000 at Morphy Auctions' November 9 Prehistoric American Artefacts sale in Denver.
The price set is a world record for a North American flaked stone artefact.
The point dates to circa 10,000-9,000 BC and was produced by the Clovis people - early inhabitants of North America who make their first appearance on the archaeological record 13,000 years ago.
Carved from green obsidian, the lot features the distinctive bifacal head that characterises Clovis points - which would have been used to hunt big game, such as mammoth.
At just over nine inches long it is the largest Clovis point ever discovered, making it a highly significant pre-historic artefact.
It was discovered in a field in Douglas County, Washington in the 1950s.
A lot of 20 motley pieces made $28,000.
Motley points can date to as far back as 1400 BC and are characterised by narrow necks and wide shoulders, with straight or slightly convex blade edges.
The lot of 20 was found in Tod Country, Kentucky and is the largest such cache known.
A rat-tail spud made from carved and polished metamorphic rock made $31,200.
Dating to the time of the Southeastern Ceremonial Complex (AD 1200-1650), spuds were likely used for unknown ceremonial purposes.
They originate from the Mississippi basin where a civilisation briefly flourished, apparently developing without outside influence despite the resemblance of its art and artefacts to those of Mesoamerican cultures.
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