By bizn_fun 
The NMS said it would be used for research but it is hoped it will go on display in future.
King David I of Scotland, who reigned from 1124 until 1153, introduced the country’s first coinage.
Alice Blackwell, senior curator of medieval archaeology and history, said it was thought all his earliest coins were created in a mint in Carlisle, Cumbria, which he took control of in the 1130s.
But she added: “This coin is really significant because it’s the first of that earliest type, the earliest coins to actually have been minted outside of Carlisle.
“It was minted in Edinburgh, so it’s the first time that we have Scottish coinage being minted in what was a core part of the Scottish kingdom.”
She said any coins found before the king’s reign could be Roman Age, Viking Age or medieval coinage.
David I later lost control of Carlisle.