When I was exploring the old microscope slides belonging to the mysterious 'Sid' that I mentioned in my previous post I came across one that was clearly home-made and was labelled as porphyritic olivine basalt from the Lion's Haunch, Arthur's Seat, Edinburgh. The hill is the plug from the mouth of a long extinct volcano, exposed after softer sedimentary rocks were eroded from around the igneous core. Polarised light microscopy reveals the crystalline inclusions very nicely.
Similar rock samples were collected on the Apollo 15 mission to the moon in 1971
Arthur's Seat is the very conspicuous hill - some might call it a mountain - almost in the centre of Edinburgh. From the right angle it looks like a resting lion and this polished thin section of igneous rock came from the 'Lion's Haunch'. Of couse, there's no way of telling whether Sid, who was apparently a chemist, prepared this specimen himself or swapped it with a geologist friend - microscope slide exchange clubs were once common - but he clearly had an interest in Scottish geology, so may have been a Scotsman......
