These minerals are typical of mantle detritus found in kimberlite that indicate that this boulder material represents cooled magma derived from the Earth’s mantle.
Garnets are a standard indicated for diamonds, and the results provide further evidence of the potential existence of an undiscovered diamondiferous kimberlite near to Lahtojoki.
The company will now undertake follow-up work.
Kimberlites tend to occur in clusters, so there is grounds for optimism that another kimberlite may be nearby.
Certainly the wider region has proved to be very rich, as highlighted by two major discoveries on the other side of the border with Russia.
“We’ve studied Lahtojoki very carefully,” says Professor Conroy, the chairman of Karelian Diamonds.
“Had it been in Botswana it would long since have been developed.”
The presence of coloured diamonds at Lahtojoki was once considered of questionable benefit. But not any more.
The precedent set by the Argyll mine in Australia, where pink diamond accounted for 5% of the stones but 50% of the profits, provides real encouragement for Lahtojoki, where 5% of the stones are coloured and around 3% are pink.
Finland doesn’t yet host any diamond operations, but if a new kimberlite can be established in the neighbourhood of Lahtojoki, then the economics of a development could become even more favourable.
Karelian is planning a major sampling programme at Lahtojoki soon.