An emerald is a precious gemstone and the green variety of the mineral beryl. Its intense green color comes mainly from traces of chromium and sometimes vanadium.

Color & Quality

Emeralds are evaluated based on the “Four Cs,” like diamonds, but color matters most:

Color

• Ranges from bluish-green to pure green

• The best gems have:

  • Medium to vivid saturation

  • Even color

  • Not too dark or too light

Clarity

• Most emeralds contain inclusions (“jardin” — French for garden)

• Eye-clean emeralds are extremely rare and valuable

• Inclusions are generally accepted more than in other gems

Cut

• Often cut into the classic emerald cut (rectangular with step facets) to reduce stress on the stone

Carat

• Large high-quality emeralds are rarer than large diamonds

Origins

Some of the most notable emerald sources:

• Colombia — considered the best; Muzo, Chivor, Coscuez mines

• Zambia — often slightly bluish-green, fewer inclusions

• Brazil — wide variety, from light to deep green

• Afghanistan & Pakistan — fine quality, sought after

• Ethiopia — newer but increasingly popular

Treatments

Most emeralds are treated to improve clarity:

• Oil treatment (traditional)

• Resin/Polymer treatments (more modern; should be disclosed)

Untreated emeralds are rare and command huge premiums.