May Birthstone

Emerald is coloured by trace chromium and sometimes vanadium. Colombian emerald is the historic benchmark for vivid warm green. Zambian material runs slightly bluer and tends to be cleaner. The internal inclusions in emerald are normal and are referred to in the trade as jardin, French for garden, and they are accepted in even the finest stones. Emerald has stood for rebirth, growth and the deeper bond of long love for thousands of years.

Emerald is 7.5 to 8 on the Mohs scale, which is hard. But the heavy internal fracturing means emerald is much more brittle than its hardness number suggests. For an engagement ring or daily-wear ring, a bezel or a halo setting is strongly recommended. Emerald earrings and pendants are easier on the stone than a ring face.

Egyptian emerald mines date back to at least 330 BC, and Cleopatra is famously associated with emerald jewellery. Spanish conquistadors brought Colombian emeralds to Europe in the 16th century, where they reached the Mughal and European courts. The Chalk Emerald, a 37.8 carat Colombian stone, sits in the Smithsonian today. Emerald has long been associated with the goddess Venus and with fidelity in marriage.

An emerald-cut emerald with diamond shoulders in yellow gold reads classic and dressy, and a bezel-set round emerald in platinum reads more modern. For an everyday-wear gift, drop earrings and pendants put less stress on the stone than a ring does. Lab grown emerald is now widely available and gives the colour at a much lower price with better clarity.

Emerald requires gentler care than most precious stones. Clean by hand with warm soapy water and a soft brush, and avoid ultrasonic and steam cleaners, which can damage the stone and remove the oil or resin treatment that most emeralds carry. Take emerald rings off for washing, cleaning and exercise.