AN English company has found diamond indicator minerals in rivers at Carndonagh, Malin and Culdaff in Inishowen, Co Donegal.
Cambridge Mineral Resources is preparing to unearth the minerals later this month. It secured the State's first diamond-prospecting licence from the Department of Transport, Energy and Communications, last August.
According to CMR managing director, Mr David Bramhill, mineral sampling of sediment taken from the rivers in Inishowen has indicated that diamonds may be hidden in the bedrock.
CMR has already discovered small blue seed-like sapphires in one of the rivers. According to Dr Norman Moles, a geology lecturer at Queen's University Belfast, although these are valuable in their own right they can also be a good diamond indicator.
Dr Moles has retained an interest in mining and the economic aspects of geology after spending some years working in Donegal looking for gold. He says he would be surprised if diamonds are found but no one has looked before.
He says geologists have long believed Donegal's old metamorphic rocks might hold valuable mineral deposits including gold, uranium and precious stones.
A Geological Survey of Ireland spokesman says the indications are that Donegal is well worth investigating.
A spokesman says: "Growing understanding of the world-wide natural occurrence of diamonds has offered more search areas and this, combined with new perspectives in Irish geology, has focused attention on northern Donegal."
The sediment samples from the three Inishowen rivers last year were sent to Australia for investigation and analysis. The results identified diamond indicator minerals two sample locations and sapphires at one location.
"We couldn't, believe the results of the tests," says Mr Bramhill. "People told us we were mad when we started our operation here. They may be forced to think again.
"Diamond-mining takes a long time because it is such a technical process. However, all our results so far warrant significant exploration and we're certainly not going to rule out finding diamonds."
Inishowen is now CMR's main Irish focus and as soon as the weather improves, the company will begin a full-scale investigation.
The company also operates in Sweden and Spain. It will be floated on the Alternative Investment Market of the London Stock Exchange this Friday.
An independent survey, by Dublin-based geological consultants Crowe, Sehaffalitzky and sociates Ltd, as part of the list in requirements of the London Stock Exchange, found CMR's Irish exploration programme for diamonds to be geologically innovative and has already produced positive results".