Most expensive emerald per carat

The 18.04-carat Rockefeller Emerald, set within a platinum and diamond ring, achieved $5,511,500 (£4,316,250; €4,927,450) – including buyer's premium – at Christie's auction house in New York City, USA, on 20 June 2017. The gem was purchased by the American jewellery firm Harry Winston. This represents a per-carat price of $305,515 (£239,259; €273,140).

The emerald was first acquired by John D Rockefeller Jr – the son and heir of the richest person ever (adjusted for inflation), John D Rockefeller Sr – in 1930, where it was the centrepiece of a brooch for his wife.

In 1948, it was converted from a brooch into its current form as a ring by the American jeweller Raymond Yard.

The most expensive emerald overall was sold at Christie's in Geneva, Switzerland, on 12 November 2024: the 37-carat Aga Khan Emerald brooch, originally owned by British socialite Nina Dyer, who was briefly married to Prince Sadruddin Aga Khan, fetched 7,765,000 Swiss francs ($8,859,865; £6,926,230).