ARTICLES
Gemstone Occurrences and Ancient Circular Impact-Scars: the Gemmology Tail Wags the Geology Dog
Numerous occurrences of transparent gemstones are in diverse ways associated with large circular scar-patterns on the Earth’s surface. These are interpreted as vestiges of the asteroid and meteorite bombardment that also scarred the Moon. Neither the existence of these circular...
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New Finds of Cobalt-Bearing Spinel Near Mahenge, Tanzania
Since November 2021, bright blue spinels have been recovered from the Mahenge region of Tanzania. These stones are cobalt-bearing and are called cobalt spinels in the international trade. The samples investigated for this article have been identified as relatively pure...
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The New Minerals Exhibition at the Australian Museum
The new Minerals exhibition at the Australian Museum, Sydney, sets a new standard of excellence for such exhibitions in Australia and is a wonderful scientific and educational resource (Figure 1a, b; Pogson, 2022). It is part of the Museum’s transformative...
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Detecting Corundum Fillers with the Long-Wave UV Torch
UV fluorescence is one of the most underrated tools used in gemmological laboratories. Standard long-wave/short-wave units as well as long-wave torches are fairly affordable and accessible yet have many uses. This author has previously discussed some of these techniques. For...
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An Interesting Pair of Earrings
At one of the monthly meetings of Western Australia’s Gem Appreciation Group, a member brought along a particularly fascinating pair of earrings that had been made in Thailand. These are shown in Figure 1. Each earring measured about 3.5 cm...
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