Isn't nature wonderful? It is summer time, you are high in the hills of Donegal, far from the madding crowd; you come across a spectacular view of Lough Foyle, some bunny rabbits, a diamond the size of a chestnut . . .

Even if you don't find a diamond, you might come across a geophysical anomaly that could turn out to be a kimberlite or lamproite. That is, if Cambridge Mineral Resources hasn't found it first.

In truth, hunting for diamonds in the hills of Donegal is not quite so easy, which is perhaps why the company's executives and scientists would not yesterday, under any circumstances, give a estimated date or volume for the gems they hope will be uncovered.

But the signs, they insisted, were good. Stream sediment samples collected on Donegal's Inishowen peninsula contained "indicator mineral grains", a lowlevel sweep in a plane recording the magnetic field of the area showed up many "anomalies".

In the diamond business, anomalies are good. They could be a rusting pile of tin cans just below the surface, an old bath in a field or a parked bus. But they could be kimberlites or lamproites, the host rocks for diamonds.

Cambridge said yesterday its hardy geophysicists had walked over all the ground, eliminated the buses and baths and were left with "approximately 20 high to medium-ranking anomalies".

"The results of the survey were very encouraging," said scientist Mr Jason Bak. "We have prioritised 10 targets for ground geophysics."

The company said its tactic would be not to drill at a series of locations, but to build up a programme - liable to begin later this year - perhaps with another company invited to participate.

And while no one at Cambridge would speculate on the volume of diamonds likely to be found, or when this might occur, the company has already applied to the Department of the Marine and Natural Resources to buy four more prospecting licences.

The geophysicists have been busy outside Ireland too. In Scotland, Cambridge feels it could close in on some sapphires. Because negotiations are still ongoing with the owner of the remote estate in question, the company would not reveal its whereabouts, but did show a lovely photograph of the site, replete with grass, rocks, heather and a stream.

More exotic still is Cambridge's involvement in the South Atlantic where, through a connection with a former director, it has acquired the mineral prospecting rights for the entire Falkland Islands.

Executives said the Falklands were "too big for Cambridge on its own", and the company was working on a joint venture agreement with other firms to begin work there.