50 Years of Gemmology by Alan Jobbins (from notes taken at the meeting by Lawrence Hudson) (This talk is similar to one given at the Midlands branch, with the addition of six slides taken in St. Petersburg during his visit six days ago. Alan's talk was accompanied by 80 slides. He spoke without notes. Because he frequently sells the rights to his images, he was unable to permit us to reproduce them here. Sometimes you have to attend the lecture.)
	Alan Jobbins
	(click to enlarge)

Alan took his degree in geology and petrology from King's London. "It was the best thing I have ever done because it has given me a reason to see the world. I have always felt very lucky to pursue my hobby."

His first professional job was on the staff of the Geological Survey and Museum where he organized the new arrangement for the Mineral Collections (based on crystal chemistry) of some 250,000 specimens. At that time much identification work was carried out with scrapings immersed in refractive index liquids and viewed with a petrological microscope. By using alternately blue and yellow light and liquids calibrated in increments of 0.005, identification of specimens was quick and easy. It was very useful in sorting out jades and their simulants -- X ray diffraction was not always easily available. He continued with mineralogical and gemmological research, curation and exhibition preparation.

In 1967 his first overseas assignment crystallized when UNESCO invited him to establish a new department at Rangoon University. Of course, the emphasis would be gemmological. He had to fight for resources against Burmese military men, but he discovered that he could get cooperation by suggesting he might complain to U Thant, who was at that time the Secretary General of the UN. Initially there was no air conditioning and instruments with compound lenses suffered badly from cement failure. Within a year many of his students went on to win FGA qualification with distinction, and two gained PhDs at Cambridge and Durham, respectively. Alan showed us pictures of the dreadful state of the proposed laboratory, and a later picture of it buzzing with activity. He showed us an image of part of the Burmese gemmological collection and invited members of the audience to attempt to identify the stones-- they were quite successful. Here also he encountered specimens of ivory showing all the classic identification features, and an orange conch pearl (20mm diameter) with pronounced flame markings.

In Sri Lanka, he visited a tortoise shell workshop, where artisans were using their feet as lasts for the chamfering of sections of shell prior to joining sections by clamping them between hot tongs. Colin Winter confirmed that the technology has not changed since Alan's visit.

He visited alluvial diamond mines in Piaui province in Brazil, and showed us pictures of the vertical (and vertiginous) tunnels dug to reach the cascalho pay strata, which, because it is alluvial, is found anywhere from 10 to 30 metres down. The vertical tunnels were connected by a network of horizontal tunnels, illuminated by light reflected off flattened gas cans. The yield of this particular mine was discouraging. In a neighboring placer mine with a higher water table, Alan showed us how the placer miners swirled the paydirt to leave an occasional diamond in the center of their pan.

At Pedro II opal occurs in situ at the Boi Morto mine at the junction of the dolerite sill overlain by sandstones. This opal resembles material from Andamooka in South Australia and has been passed off as such. At Roca, in a nearby valley, opal was recovered from alluvial deposits and may be of high quality. Further south, at Varzea Grande, orange common opal formed in joints in wall-like dykes. The dykes are vertical, approximately 2 meters thick, and may run hundreds of meters horizontally.

In the Pailin region of Cambodia, he visited the ruby and sapphire mines and showed a picture of an ingenious sieving machine with girl gem sorters squatting in full sun, watched by a group of overseers shaded by black umbrellas who in turn were being watched by another group of overseers in the shade. He sold this image to Time-Life.

Alan visited the Yadanakadekada Mine in Mogok district, Burma, which I include to give Google something new to index. Fine ruby and sapphire and other gems were produced from this relatively sophisticated mine.

He showed us images of the jade emporium in Mogok with its vast range of boulder from Upper Burma. The boulders were usually sliced, showing a fantastic range of colors and patterns.

Six days before his lecture, Alan visited St. Petersburg. He showed us pictures of the newly re-opened Amber Room at the Catherine Palace, plus two vases apparently cut from single blocks of lapis lazuli and malachite, respectively.

Alan had worked in many other locations -- he showed us some of the most interesting.