Necklace in 18k (750 thousandths) yellow gold (acid-etched) and platinum in gourmette link with central round brilliant-cut old diamond (close to old European), G-I, SI approx. 2.20 ct. Diamond hallmarks 750 and PT 950. Diamond size: approx. 8.45 x 8.32 x 5.12 mm. Necklace length: 40 cm. Gross weight: 36.1 g. A little trick is used on this necklace. To make the gold a little more matt and the central diamond even more brilliant, the gold has been worked with an acid solution to transform it slightly without affecting its solidity. If you don't like very shiny yellow gold, this is your solution. The gold then turns orange thanks to the copper content in its alloy, and that's it! In the 1980s, the acid technique was widely used by designers to give very special textures to their composition. In this case, the chain would go almost unnoticed on matt skin, leaving the central diamond to take centre stage!