Dr Smart attended Fortrose Academy and later Aberdeen University and was always fascinated by chemistry and geology.

He joined the construction firm Fosroc in 1984 and was seconded to South Africa in about 1987 for an initial two-year contract, which turned into a career. He last visited the Highlands at Christmas, and planned to retire as technical director of the mining support company next year and return to the Black Isle.

Jan Franek, group technology GM for Minova, said: "Rod was really a highly-respected employee with friends and colleagues around the world. He was a world expert in cement and grouting systems. We will use the results of his scientific and research work for many years to come."

(Right: Tekfoam)

Director of Minova's South African operations, Donald O'Connor, said Smart "planning to retire at the end of this year, I have a strong suspicion that he would have remained active in his field and we would probably still be calling on his advice for many years to come. He had a few really clever rock-support ideas and we hope that we will be able to honour his legacy by bringing them to fruition."

The company are reported to plan to present an annual award in his memory.