An award-winning scientist who invented scientific instruments at his Belsize Park firm has died aged 101.

James Nelson, of Lyndhurst Road, Hampstead, won countless awards for his scientific achievements throughout a career spanning many decades.

He developed a range of scientific instruments still being used today at his Belsize Lane-based firm McCrone Scientific Limited, which he founded in 1964.

His close friend and former colleague Sara Mark, 73, of East Heath Road, Hampstead, said: “He was a wonderful and most versatile person. He was a very able man. I worked for him for nearly 40 years and he had an extraordinary, amazing mind.”

Mr Nelson was born in 1913 in Scotland but attended school in Canada for a time. He ended formal education aged 14 to support his mother and sister at home but not before achieving the highest exam marks at his school.

He returned to the UK in the 1930s, where he met Doris Holden. They were married in 1942 and were together for 67 years until her death.

After working as a chemist, he undertook a PhD at Cambridge University after impressing the admissions team despite his lack of formal education.

He specialised in crystals and would later work in the field of gemmology, for which he received the Gemmological Association’s Research Diploma in 1993. Only six people have ever won the award.

But his main love was invention, and his McCrone micronising mill was in high demand from the scientific community for many years.

Ms Mark said: “He was constantly inventing. His thought process was so amazing.”