Van Cleef & Arpels Panther Brooch with Diamonds and Emeralds

• Assay / Assayed - Assaying is the testing of a metal, most commonly silver and gold to determine its ingredients and quality. In Britain, once an item of silver or gold has been assayed, a mark is stamped on it, certifying its purity. Known as hallmark, it derives its name from the Guild Hall of the Goldsmiths' Company, who recieved its Charter in 1327 giving it the power to assay and mark articles of gold and silver.
• Emeralds - Emeralds have been used in jewellery making for thousands of years, and are prized for their deep green colour, which is caused by the presence of chromium and vanadium in the mineral beryl. Because of their rare colour, emeralds are often more valuable than diamonds of a similar size and quality. In jewellery making, emeralds are typically cut into round or oval shapes to maximize their color and clarity. They are often set in gold or platinum and used as the centrepiece of a piece of jewellery, such as a ring or necklace. They can also be used in combination with other gems, such as diamonds, to create intricate and beautiful designs.
• Onyx - Onyx is a form of agate, used from antiquity and popular again in the 1920s and 30s. European onyx is generally green, but can be many other colours, and can contain bands of black and/or white.
  
  This multicoloured stone is widely used for table tops, lamp bases and in jewellery. Some types of onyx are also used for cameos of which the upper white layer is cut away to reveal the colour beneath.

This item has been included into following indexes:

• brooches, depicting - wild cats: lion, tiger, panther 120
• brooches, diamond
  • diamond and emeralds 214
  • diamond and enamel 143
  • diamond and onyx 46
• brooches, gold - gold with enamelled decoration 411
• Van Cleef & Arpels (France) - brooches, designers 37