The Kakanui coastline south of Oamaru may be harbouring diamonds.

Auckland geologist Barry MacDonnell, of Lodestar Resources, has applied to government agency Crown Minerals for a prospecting permit to take samples from 107 square kilometres of Kakanui land in the search for microdiamonds.

He said the first stage of diamond exploration in the area had been completed as early as 1905 when an academic geologist identified indicator minerals pointing to the presence of diamonds.

'The next stage is to check for microdiamonds, diamonds smaller than 0.4mm. Obviously it is all speculation at this stage.' he said today.

The permit would allow Mr MacDonnell only to take surface samples, and did not allow him to take samples from private property.

Mr MacDonnell said he would probably only sample outcrops of Kakanui mineral breccia, a form of broken-up rock unique to the area found along the coastline. It had been pushed up from the earth's upper mantle, or 'the bit of the earth that lies along the crust.'

'Samples could be collected by hand and from beach gravels. I'll have those screened to a finer particle size. The samples get sent to a lab in Australia and have to be checked under a microscope. You need to be very specialised to recognise a microdiamond,' he said.

Microdiamonds indicated there could be macrodiamonds in the area, which would need to be drilled for in the third stage of exploration, requiring an exploration permit.

He would consider finding an investor to begin drilling if microdiamonds were discovered.

Mr MacDonnell expected to begin taking samples from the area by himself between July and September.

The permit was for two years, which would give him time to consider whether there was any economic value in the search, he said.

He had known about the area's diamond potential for 10 years. Increased diamond exploration in Australia spurred him on to action.

'There are 20 companies listed on the stock exchange exploring for diamonds. I figured if I didn't, someone else would be bound to do it.'

Lodestar Resources was family-owned and had interests in other exploration companies.

Rebecca Anderson
Oamaru Mail 20 March 2003