Carnelian, 16.26 grams, 43 cm, 17 inches. Indus Valley Culture; Bronze Age, circa 2600 - 1600 BC. A re-strung carnelian necklace, which has 56 ovoid shaped ancient carnelian beads, etched with geometric designs. The technique of painting the surface of a finished carnelian bead with natron [calcium carbonate] and then baking the mineral on appears to have been invented around 2500 BC by Indus Valley craftesman, possibly to imitate banded agates. This technique was also adopted by the Mesopotamians and later by the Persians. Etched beads may well have been traded from the Indus Valley to Sumer as early as 2500 BC. Reference: Thames & Hudson, The History of Beads from 30,000 BC to the Present, page 181-2; No. 600, a-c. Extremely fine condition and wearable. Provenance: from an old English collection; found Indus Valley, Pakistan.