The greatest sparklers going under the hammer A late 19th century sapphire and diamond brooch. Estimated selling price: £400,000 - £500,000. At over 14 carats, this treasure was once owned by the Hon Evelina Rothschild, and could have been a wedding present to the bride when she married Clive Behrens in 1899. The sapphire, of Kashmir origin, bears no indications of heating and is rare in its finely proportioned cut and richly saturated colour