Emerald

An amulet believed to protect against evil spells.

Emerald has enthralled the elites of civilizations with its stunning beauty and symbolic power for over 6,000 years. The name comes from the old French
“esmeralde” through Latin “smaragdus” through Greek “smargdos.” One of the world’s first emerald mines in Egypt was named “Cleopatra’s emerald mine” for her lifetime love affair with the stone. Emeralds from what is now Colombia were part of the plunder when 16th century Spanish explorers invaded the New World. The Spanish, who treasured gold and silver far more than gems, traded emeralds for precious metals. Their trades opened the eyes of European and Asian royalty to emerald’s majesty.

Color
Emerald is the green to bluish green variety of the mineral beryl colored by trace elements of chromium and vanadium. The most desirable emerald colors are
bluish green to pure green with strong to vivid color saturation and medium to medium-dark tone. An emerald’s hue, tone and saturation determine its value.
If the hue is too yellowish or bluish, the stone is not an emerald.

Clarity
Emeralds are inherently more included than most other gemstones. Eye-clean stones are very rare. Unlike most other stones, visible inclusions are acceptable in emeralds unless they are so numerous as to affect the transparency of the stone. The most prized emeralds are highly transparent with even color distribution and no eye-visible color zoning.

Sources
Colombia, Brazil, Zambia and Zimbabwe supply the majority of emeralds on the international market. Colombia produces what many consider to be the highest quality and volume of emeralds. The Colombian emerald has been widely accepted as the world’s most desirable pedigree and its mines remain a prized locality to this day.

Treatments
Filling surface-reaching fractures or fissures with oil can make them less noticeable, which increases transparency and improves the apparent color of an emerald. Since oil can leak or dry after a period of time, the use of paraffin or resins are sometimes used as a more stable filler.

Major Sources
Afghanistan, Brazil, China, Colombia,
Ethiopia, India, Madagascar, Nigeria,
Pakistan, Russia, Zambia, Zimbabwe

Mineral 
Beryl

Mohs Hardness
7.5 to 8

Toughness
Fair to Good

Color
Green to bluish green

Birthstone
May

Care and Cleaning
Since the great majority of fashioned natural emeralds contain filled
fractures, it’s risky to clean them ultrasonically or with steam. Ultrasonic
vibrations and hot steam can cause oil or unhardened resin to sweat out
of fractures. Using warm, soapy water coupled with gentle scrubbing is the
safest way to clean emeralds.

Source: The Passion of Colored Gemstones by G.I.A.