A Swedish porphyry (Röd Rännås) tazza, early 19th century | Coupe en porphyre suédois (Röd Rännås), début du XIXe siècle

Although the word 'porphyry' comes from the Ancient Greek word for 'purple' (πορφύρα), its spectrum of colours ranges from blacks and greys to orangey reds, and even greens. Revered in Antiquity for its associations with royalty and imperial power, the sole source of porphyry known in the ancient world was in Egypt; in 1731, though, it as also discovered in Älvdalen (Elfdal) in Sweden, and Sweden became a significant producer of fine porphyry objects in the late-eighteenth and early-nineteenth centuries. Tazze were a popular form, and two 1830s examples with comparable octagonal bases are pictured in Porfyr; En utställning kring föremål från Älvdalens Gamla Porfyrverk, ed. Hans Sundblom et al (Stockholm: Bukowskis, 1986), p. 93. A similar example in red porphyry was sold at Sotheby's New York, 13th April 2016, lot 77.