James Garriock, 43, and Terrence Rossiter, 47, both of Salisbury, Wiltshire, were sentenced to nine months' jail, suspended for a year, because of the "exceptional circumstances" of the case.
The men unearthed more than 500 Bronze and Iron Age artefacts in a field near Salisbury 10 years ago without the landowner's knowledge.
They then made more than pounds 5,000 each selling most of the six-figure value haul of tools, weapons, ornaments and jewellery - some 4,000 years-old - to a dealer. Some of those items were later bought by Lord McAlpine, the former Conservative Party treasurer, who had no idea of their real origin.
Passing sentence at Knightsbridge Crown Court, Judge Christopher Hordern QC said the two men appreciated that they should have reported what they found.
But a long time had elapsed since they discovered what had since become known as the Salisbury Hoard and he could understand "the excitement and the degree of temptation which was placed before you". They had changed their pleas to guilty as soon as they understood what they had done was illegal.Reuse content