Gem Library

BUYER’S OVERVIEW:
Emerald is classified as one of the traditional four precious stones along with sapphire, ruby and diamond. High quality stones are very limited in nature but gems of good color and size are available (for a price).   Emerald typically exhibits a color range of medium to dark green to bluish green and the rich color is derived from chromium, vanadium or a combination of both. The term “Columbian” Emerald has often been used to describe vivid, slightly bluish green stones of medium, to medium dark color, no matter what their actual geographic origin. Emeralds of lighter color are sometimes called “Brazilian” even if they are mined in Africa.

COLOR:
Medium to dark green to very strongly bluish green.

APPEARANCE:
Transparent to opaque, Emerald is a Type III gemstone and is usually highly included.

Phenomena:
Emerald can exhibit the phenomena of Chatoyancy, a striking three dimensional effect typically seen in tiger eye quartz.

SIZE RANGE:
Melee (0.01 carat) sizes to 4 carats; high quality stones over 1 carat are rare, however faceted stones over 100 carats are known.

TYPICAL CUTTING STYLES:
Transparent: faceted (emerald cut common)
Translucent: cabochons, beads and carvings

POSSIBLE ENHANCEMENTS & TREATMENTS:
Oiling and fracture filling is a method commonly used to improve clarity and color however this treatment is not stable and should be avoided. Non-standard treatments also use green colored oils and hardened, epoxy-like resins. These treatments dramatically improve the appearance of the gems and sometimes add weight but may dry out and change color over time.

HARDNESS:
7½ to 8 on the Mohs scale.

BEST USE OF THE GEMSTONE:
Emerald is not a strong gemstone and as such, earrings, pendants, pins, and tie tacks are probably the safest choice for this stone. Rings should be limited to occasional wear and the stones should be set with a protective setting.

CARE & CLEANING:
It is best to never expose colored gemstones to cleaning solvents or chemicals of any kind.
Common cleaning methods include:
Ultrasonic: never
Steamer: never
Warm soapy water: safe
Reaction to Chemicals: can be damaged by acids.
Reaction to Heat: may cause fracturing or complete breakage
Stability to Light: stable, except possible fading to stones treated with green oil

INTERESTING FACTS ABOUT THIS GEMSTONE:
Emerald is the most precious stone in the beryl (BARE-ul) family. The name emerald comes from the Old French “esmeralde” that derives from the Greek “smaragdos”, both translating to “green stone”. The name may not be impressive, but Emerald’s reputation goes far beyond its simple name. The wonderful green of the Emerald is unparalleled in the gem world. It is classified as one of the traditional four precious stones along with sapphire, ruby and diamond.

Emeralds have been held in high esteem since ancient times. The Turkish sultans loved Emeralds and in Istanbul’s Topkapi Palace there are exhibits of jewelry, daggers and writing-implements, all lavishly adorned with Emeralds and other gems. The Viennese treasury has a vase, cut from a single Emerald crystal of 2205 carats. Queen Elizabeth II, has a fabulous collection that includes the “Cambridge and Delhi Dunbar Parure”, a fantastic suite of Emerald jewelry that includes an Emerald diadem.  

One of the world’s largest Emeralds is the “Mogul Emerald”, dating from 1695 and weighing in at 217.80 carats. One side is inscribed with prayer texts, the other with magnificent floral ornaments. This legendary Emerald was auctioned by Christie’s of London and sold to an unidentified buyer for $2.2 million in 2001.

DESIGNATION:
Birthstone for May, Cancer (June 22 – July 22), 20^th and 35^th anniversary.

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