Robert Webster FGA was originally in the jewellery and pawnbroking trade, and won the Fellowship Diploma of the Gemmological Association of Great Britain with distinction in 1934. In 1946 the same association awarded him their coveted Research Diploma and in that year he joined London Gem Testing Laboratory, then in Hatton Garden, where he remained until he retired in 1971. He was a noted lecturer and demonstrator in various London colleges for decades and an honorary visiting lecturer to the Detective Training School of the London Police. He travelled widely, lecturing, visiting gem laboratories and mining and cutting centres in many parts of the world. E. Alan Jobbins FGA was a professional mineralogist and gemmologist at the Geological Museum in London for thirty-five years. He has been a consultant to the United Nations and the British Government Overseas Aid Programme and has advised on the setting up of gem testing laboratories, and has worked on the assessment and development of gem deposits in many parts of the world. He was editor of the Journal of Gemmology for many years.