Emerald

Chemical Composition: Be₃Al₂SiO₆

By Angela Hui

Class 3a.htm

Entering into the world of emeralds is truly fascinating! Emeralds come from all over the world and are known for its impurities such as scratches and cuts. Emeralds that have no impurities are very rare and have a high value. Let's enter the wonderful world of emeralds and explore!

Link to next emerald page>>
Link to gemstone homepage>>

Contents

Facts + Lore

Difference between Synthetic/Lab created and natural emeralds

Where and how the stone was mined

Demand and Uses

Striking Features

Ways to determine Emeralds from other similar stones

Map of where the stone was mined

5 pictures of different cuts or types

Color or Color Range

Color/Color Range: Medium to dark green or a bluish green.

Where and How the Stone was Mined

Emeralds are mined in Columbia, Zambia, Brazil, Pakistan, etc. Generally they are found by cutting through the stratification, although in some instances the cut is a parallel one and consist mainly of calcite and pyrite with quartz, emeralds, fluorite and rarely, parisite (Ca (Ce, La) 2 (Co3) 3h2) and codazite (dolomite with Ce). Emerald mining is typically a labor-intensive process involving may people watching conveyor belts for a flash of green. Emerald mining does not typically require a huge capital investment in equipment, but beryllometers and color sorters are used on some occasions. There are no harmful chemicals involved in the mining process and is the cost far less than the US$600 million required to mine diamonds.

Map of Where Emeralds are Found

5 Different Types of Emeralds

Zambian Emerald Trapiche Emerald Brazilian Emerald

Columbian Emerald Cat's Eye Emerald

Demand & Uses

Transparent emeralds are faceted in gem cuts for jewelry and translucent ones are cut and polished into cabochons and beads. Trapiche emeralds are also cut into cabochons, making glamorous and exquisite jewelry pieces. A very small number of emeralds display asterisms but these are cut into cabochons, too. Demand is very high because it is considered to be more precious than diamonds.

Cabochon - Gem without facets that is highly polished and has smooth, rounded edges.

Striking Features

Its beautiful green color, combined with durability and rarity, make it one of the most valuable gemstones. Emeralds are harder than most stones. It is a seven to eight on the Moh’s Scale of Hardness. An emerald’s deep green color distinguishes it from any other stone. Emeralds are notorious for their flaws. Flawless stones are very uncommon, and are noted for their great value. Emeralds may develop internal cracks if banged hard or if exposed to extreme temperature change. Emeralds that were treated to hide internal flaws should never be cleaned with an ultrasonic jewelry cleaner, nor should they be washed with soap. These actions will remove the oil and expose the hidden internal flaws.

Ways to Determine an Emerald from other Similar Stones
Green sapphire may resemble emerald, but its high hardness distinguishes it. An emerald is a 7.5 to 8 on the Moh’s hardness scale. That’s considerably high considering that the highest is ten, the diamond. Garnet and zircon rarely achieve a deep green like emerald. The emerald is prized for its beautiful color. Diopside and dioptase are considerably softer than emerald. Green tourmaline can only be distinguished by its difference in optical properties.

Difference between synthetic, lab created and natural stones
•    Synthetic emeralds are emeralds that are produced in a laboratory. Unlike simulated emeralds, which look like emeralds but differ from natural emeralds physically and chemically, synthetic emeralds duplicate natural emeralds entirely. In the 1960’s, a new method of hydrothermal flux synthesis was applied to Emerald creation. This method is largely used today in the creation of synthetic Emeralds. The technique involves dissolving the crystal nutrients in an acidic solution of water and chemicals at high temperatures and pressures, with crystallization occurring in a cooler chamber in the reactor. These early versions of the present-day hydrothermal Emerald creation were known as Emerita and Symerald. Synthetic emeralds have a characteristics of veil or wisp-like, liquid inclusion.
•    Natural: Emerald crystals may form in hydrothermal veins if the necessary conditions are present and if the necessary elements (like beryllium) are present. These hydrothermal veins occur when hydrothermal fluids escape from magma deep in the Earth’s crust.
These fluids may contain adequate concentrations of the elements necessary to build a natural Emerald crystal. When they do and if the conditions are optimum, an Emerald crystal may begin to take shape as the hydrothermal fluids begin to cool in deposit veins that have fractures in them. Almost all Emeralds that are sourced from Colombia are formed in this manner. Many of these Colombian Emeralds are associated with calcite deposits that are also formed in the hydrothermal process.
Not all Emeralds are formed in a hydrothermal vein. Some Emeralds are formed in pegmatite deposits. Pegmatites are similar to hydrothermal veins, except that the primary agent in hydrothermal vein formation is hot water and the primary agent in pegmatites is magma, or molten rock. As this magma begins to cool, some elements are left in solution in the remaining fluid. When the necessary elements are present and if conditions are perfect, Emerald crystal formation may occur in these pegmatites.

Color
Medium to dark gree to bluish green.
Other interesting Facts or Lore
•    Luster is vitreous.
•    Emerald is in the mineral class, Beryl. Beryl also contains other, lesser known gem varieties, such as aquamarine and heliodor. Pure beryl is white but an emerald's green color is caused by chromium impurities
•    Emerald is the most famous and favored green gemstone. Its beautiful green color, combined with durability and rarity, make it one of the most valuable gemstones.
•    Deep green is the most desired color in emeralds. Pale emeralds are not called emeralds, but "green beryl". Sometimes, they are heat-treated, in which they become aquamarine.
•    A rare and prized form of emerald, found only in the Muzo mining district of Colombia, is a very unusual form of this gem. This emerald, known as "Trapiche emerald" is characterized by star-shaped rays that emanate from its center in a hexagonal pattern.
•    Emerald is the birthstone of May.
•    There are many types of varieties of emeralds. Here are some well known ones.
Colombian Emerald – This emerald is from Colombia. This emerald is usually of exceptional quality.
Brazilian Emerald – This emerald is from Brazil. The Brazilian emeralds are generally a lighter color than the Colombian emeralds. (The term Brazilian Emerald may also refer to green Tourmaline from Brazil.)
Zambian Emerald – This is a quality emerald from Zambia
Trapiche Emerald – This emerald with black impurities in the form of a six-rayed star
Cat's Eye Emerald – This emerald exhibits a cat's eye effect. Cat's eye emerald is very rare and only exists on paler emeralds.
•    Beware!! There are some synthetic emerald names to look out for. Emeralds have been synthetically produced since 1848. However, only recently have synthetic emeralds been available of the market. Here are some names for synthetic emerald to watch out for:
Biron Emerald
Chatham Emerald
Gilson Emerald
Kimberly Emerald
Lennix Emerald
Linde Emerald
Regency Emerald
Zerfass Emerald

Glass dyed green is also a major emerald simulator. Here are some totally fake names for some of these glass-dyers.
Broghton Emerald
Endura Emerald
Ferrer's Emerald
Medina Emerald
Mount St. Helens Emerald
Spanish Emerald

Other false emerald names include:

African Emerald – Sometimes they can be green fluorite
Bohemian Emerald – Sometimes they can be green fluorite
Cape Emerald – sometimes prehnite
Congo Emerald - dioptase
Emeraldine - chalcedony dyed green
Emeraldite - green tourmaline
Evening Emerald - peridot
Indian Emerald - quartz or chalcedony dyed green
Lithia Emerald - hiddenite
Mascot Emerald - emerald doublet
Night Emerald - peridot
Oriental Emerald - green sapphire
South African Emerald - green fluorite
Tecla Emerald - emerald doublet
Transvaal Emerald - green fluorite
Uralian Emerald - demantoid garnet
•    Emerald is the traditional gift for the 55th wedding anniversary.
•    Colombian emeralds are among the world's most beautiful, with rich grass-green coloring that's often kissed with a touch of blue. Quality emeralds are also found in India, South Africa, Afghanistan, Pakistan, Russia, and Zimbabwe.
•    Emeralds are traditionally thought to enhance the clairvoyance of their wearers.
•    Egyptian emeralds were introduced to the world about 4,000 years ago, but the stones from those mines are a duller green and are not considered high quality by today's standards.
•    Mummies were often buried with emeralds. The gemstones were also popular in ancient Rome.
•    Traditionally, emeralds are worn to promote healing and enhance love and contentment.
•    The name emerald derives from the Greek word smaragdos meaning "green stone" and in earlier times, the word not only referred to emeralds but also any other stones that were green in color.
•    Emeralds are formed by rising magma and metamorphism. Deposits are therefore found in or near pegmatite veins.
•    For thousands of years, almost all of emeralds came from Egypt. "Cleopatra’s Mines" worked first by the Egyptians, and then by the Romans and the Turks, were in nearly continuous operation from about 330 B.C. to 1237 A.D. "This monopoly lasted until the Spanish conquistadores arrived in South America in the early part of the 16th century. Shortly afterward, Jimenez de Quesada conquered what is now known as Colombia. Some years later, in 1558, the Spaniards located a mine at Muzo. The emeralds found there were breathtaking in both quality and size. The Spaniards promptly seized control of the mine and enslaved the local population using them to do the exhausting, dangerous work of digging out the gems. Within a few years, a veritable flood of big, almost flawless emeralds reached Europe, many of them finding their way into the hands of the Ottoman Turks, the Persian Shahs, and even the royalty of India. These stones were sculpted and engraved, becoming the foundation for many priceless jewel collections.
•    Specific Gravity: 2.67- 2.78
Refractive Index: 1.576-1.582
Crystal System: Hexagonal (trigonal); hexagonal prisms, columnar
•    Cleopatra prized her emeralds more than any other gem.
•    The Romans also loved emeralds because, as ancient scholar Pliny said, "nothing greens greener."
•    The Moguls of India loved emeralds so much they inscribed them with sacred text and wore them as talismans.
•    The first emeralds were mined in the deserts of Egypt near the Red Sea in what were known as Cleopatra's Mines. Egyptian emeralds mined today are small and dark stones.
•    According to legend, the wearing of emeralds not only cured a wide range of ailments, including low I.Q and poor eyesight, but also enabled the wearer to predict the future.
•    Emerald has been cherished since 4000 BC, when it was traded at the earliest known gem market in Babylon.
•    Emperor Nero wore emerald sunglasses to watch the gladiators.
•    One legend says that Satan lost the emerald from his crown when he fell. The emerald was shaped into a bowl which the Queen of Sheba sent to Nicodemus. Christ used the bowl at the last supper and Joseph of Arimathea used the bowl to catch blood from the cross, founding the order of the Holy Grail.
•    The Incas had an emerald goddess, a fabulous emerald the size of an ostrich egg.
•    The ancients prized emeralds as the symbol of love, rebirth, and eternal youth. Because the rich green color of emeralds reminds of spring, it has been treasured for thousands of years by different cultures all around the world.
•    Legend says that emeralds were supposed to melt snakes eyes when they gazed upon them.

RESOURCES

www.minerals.net
www.mineral.galleries.com
www.gemstone.org
www.zales.com