Amethyst under polarized light Size:M: 60 x 45cm View from the River Thames

View from the River Thames showing boats and figures on the water

Interior view of the dining room at the Cock Tavern

and the city must surrender soon

Plate 16 from the book Icones rerum naturalium

Amethyst under polarized light Size:M: 60 x 45cm View from the River ThamesSixteen figures showing specimens of amethysts viewed under polarized light and exhibiting veined structures. Brewster notes in his text: 'The observations are the result of an immense variety of experiments, which accidental circumstances put it in my power to make upon this interesting mineral. Having access to whole bagfuls of amethystine pyramids from the Brazils, in the possession of Mr Alexander, lapidary in Edinburgh, I have examined some