Emerald: A green colored Gemstone

Emeralds are very fascinating gemstones. The lively luminosity of its colour makes the emerald a unique gemstone. Fine quality emeralds are some times costlier than diamonds.

Emerald gemstones are beloved because of its pleasant green color. Green color is considered as symbol of germination. Ancient and medieval Indian gemologists compared emerald color with green leafs of Margosa. Green is the color of peace, love and harmony. Color of Venus (goddess of love in Roman culture) is green. Green is regarded as the most natural and the most elemental of the liturgical colours The Catholic Church. It is the auspicious color of Islam and it is represented in National flags of many Islamic countries. Tri-color Indian National flag also have green that represents creativity.

We can find traces (of emeralds) in the history as old as in the Vedic and Jain texts of India. A Jain text in Prakrit language describes color of two Jain Teerthankaras as “Maragaya ghanasanniham” where “Maragaya” means emerald. Original source of the word emerald is the Prakrita word Maragaya. Prakrita Maragaya becomes Marakata in sanskrit. Sanskrit word, marakata, (meaning emerald) travelled to semetic izmargad. The word "emerald" in English is derived from Latin smaragdus via Greek smaragdos.

Thakkur Feru, Court Jewelers to Badshah Ala-ut-din-Khiljee (14^th Century) has described about quality, sources and value of emeralds in his book “Ratna Pariksha” where the word ratna Pariksha means identification of gemstones. The book is written in Apabhransha, a medieval Indian language.

Emerald is a variety of the mineral beryl [Be₃Al₂(SiO₃]₆. The mineral is a compound of Beryllium, Aluminium, Silicon and Oxygen. The beautiful green color is due to presence of chromium and sometimes vanadium. Beryl has a hardness of 7.5 - 8 on the 10 point Mohs scale. Presence of inclusions makes the stone crisp.

Emeralds are graded using five basic parameters, the five Cs of Connoisseurship; Color, Crystal, Cut, Clarity and Carat weight. Crystal is used as a synonym for transparency. Normally, in the grading of emerald transparency is the most important criterion and color is considered a close second. Both transparency and vivid green color are necessary conditions for an emerald to be considered as fine.

Emerald tends to have numerous inclusions and surface breaking fissures. 10X magnification is the standard for grading clarity in diamonds but emerald is graded by naked eye.

Clean diamonds are generally called eye glass clean but eye clean is the word for emeralds.These are considered as flawless. Eye glass clean emeralds are extremely rare. Most of the emeralds are treated with oil or oil like substances. Due to high level of inclusions most of the emeralds are cut into cabochons and beads. Only few are faceted into cut quality.

Instead of hardness of Emerald its brittleness and its many fissures make it prone to scratches and cracks. Cutting and polishing of emeralds are rather difficult. Cutting, shaping and faceting emeralds present a special challenge even for a skilled gem cutter because of the frequent inclusions.

Gem cutters have developed a special cut just for this gem “the emerald cut”. This rectangular or square cut with its bevelled corners protects this beautiful gemstone from mechanical strain. Trained artisans cut emeralds in many other shapes i.e. oval, round, pear, heart and marquise.

If the rough contains much inclusions it is cut into a cabochon or beads. Cabochons are also cut in different shapes e.g. octagon, oval, round, pear, heart, sugar-loaf and marquise. Some other shapes are also developed in recent times for emerald cabochons.

Idar-Oberstein in Germany, New york in the US, Israel and Bogota in Colombia are some of the emerald cutting and polishing centers. The cutters in these regions normally cut fine quality emeralds with no or less inclusions. They can not cut inclusive emeralds. Cutting and polishing of inclusive emeralds are extremely difficult and needs special skills.

However, Jaipur, India cuts the maximum quantity of emeralds in the world. Jaipur can cut emeralds with higher level of inclusions. Traditional skills of Jaipur gemstone dealers and artisans enable them to shape and cut highly inclusive emerald rough stones whereas most of the cutters in other regions reject these highly inclusive pieces.

There are emerald mines in different parts of the world. Colombian emeralds are generally considered as the best because of their transparency and fire. Sandawana emeralds from Zimbabwe are very rich in color and fetches high price. Good quality Sandawana emeralds are rare nowadays. Main sources of emeralds at present are Zambia and Brazil. Though Zambian emeralds are rich both in color and transparency these generally have a blue tint. Russian emeralds are transparent but generally have light color. Swat in Pakistan-Afghanistan border produces very high quality emeralds with rich color and transparency but due to huge cracks these can be cut only into small pieces. Bigger sized pieces from Swat are extremely rare. Panchsheer is also a source for good quality emeralds. Some other sources are India, Pakistan, Afghanistan, Egypt and Madagascar.

Emeralds are considered among Navaratna in India. Indian astrologers prescribe emerald for planet Mercury. The gemstone also represents two Zodiacs Gemini and Virgo. Emerald is believed to be the gemstone for intelligence and agility.

Western astrologey believe emerald as a birth stone for the month May.

Emerald gemstone has medical properties too.