Tuesday 30 December 2014

Navratana



Gems and jewelry have been an integral part of our culture from times immemorial. Even our ancient scriptures make a special mention of gems and how these gems can influence one’s life. In the context of gemstones Vedas have given utmost importance to Navratana. The term navratana is of Sanskrit origin and it literally means a group of nine gems.

Navratana or the nine gems represent the nine planets and it is believed that movement of these planets affect the course of human life. Along with this, each of these gems have therapeutic properties. In a navratna ornament there is a specific order in which these stones should be set.
NAVRATANA ARRANGEMENT

These nine gems are-
Ruby - ruby represents the planet sun. This planet influences the leadership qualities in an individual. The Indian name of ruby is manak.

RUBY


Natural Pearl - representative of the planet moon. Pearl is said to have properties which helps in calming one’s mental state. The Indian name for the gem is moti.

PEARL


Red Coral – representative of the planet mars. Coral is said to give courage and strength. The Indian name is moonga.

RED CORAL


Emerald – representative of the planet mercury. This gem rules the intellect in an individual. The Indian name is panna.

EMERALD


Yellow Sapphire – representative of the planet jupiter and it is worn for prosperity and good luck. Along with this it  helps in spiritual advancement. This gem is known for its various astrological benefits. The Indian name is pukhraj.

YELLOW SAPPHIRE


Diamond – representative of planet venus. This gem symbolises beauty and luxury. The Indian name is heera/vajra.

DIAMOND


Blue Sapphire – representative of the planet saturn. This gem is said to give extreme results to the wearer, either positive or negative. The Indian name of blue sapphire is neelam.

BLUE SAPPHIRE


Hessonite Garnet – representative of the planet rahu (the ascending node of the dragon). This planet is said to have karmic influences. The Indian name of the gemstone is gomed.

HESSONITE GARNET


Cat’s Eye Chrysoberyl – representative of the planet ketu (the descending node of the dragon). This planet is also said to bring fame and prosperity. The Indian name of the gem is vaidurya/lehsunia.

CAT'S EYE CHRYSOBERYL



Union of these nine gems is extremely powerful. Wearing these gems individually affect the planets associated with them, but wearing navratana has a positive impact on all the planets and thus, it enables one to lead a life of peace and prosperity. Nonetheless,  navratana should always be worn after consulting a genuine astrologer.


*The Author is a Colored Stone Graduate from Gemological Institute of America, Mumbai and a Diamond Graduate from Solitaire Diamond Institute, Bangalore. She also holds a Diploma in Jewelry Designing & Manufacturing from Jewelry Product Development Centre, Jaipur. She also blogs at 'The Jewel Affair'.

*Picture Courtesy: Google Images

Tuesday 23 December 2014

Kundan - Meena


India is a country known for its diverse forms of art and craft. This is one of the biggest factors that draws a lot of attention from the west. International designers constantly draw inspiration from our rich cultural heritage.

Jewelry is one such field which exquisitely reflects our majestic legacy. Various jewelry arts like kundan - meena, pachchikam, jadau etc have represented our royal treasures for centuries together. This post will bring to you one such unique jewelry art – Kundan – Meena.

KUNDAN MEENA JEWELRY


Kundan literally means pure gold and Meena refers to the enamelling work which is done on the reverse side of the jewelry.  In this technique silver foil backing is given to the stones and pure gold (24 K) is pressed between stone and its mount to elevate the look of the gems. Usually polki, emeralds, rubies and garnets are used to create kundan jewelry.

This art form took birth in Rajasthan. Jaipur and Bikaner were the two places where skilled craftsmen practised the art to perfection. The Mughal and Rajasthani royalty were adorned with Kundan – Meena jewelry. It flourished in the rule of the Mughals and is till date making a fashion statement.

MUGHAL RULERS ADORNED WITH KUNDAN MEENA JEWELRY

Captivating jewelry is created with this style, however the process is elaborate and labor intensive. It involves a series of steps to accomplish the desired results.

First and foremost, according to the design provided a basic frame is created using thin metal strips. These metal strips are soldered on to a metal back to create compartmets. After putting the design together,  heated natural resin or laakh is poured into the compartments. Laakh  is what holds the gem in the setting.

FRAMEWORK

In the next step designs are engraved on the reverse side to fill in the enamel. Powdered colored glass/enamel is filled in the engraved areas and heated to fuse the enamel on the metal. Enamelling is a tedious job and requires a lot of scrubbing and finishing.

MEENAKARI 

Thereafter, the gems are given a silver backing to enhance their beauty. Now, these gems are pressed on to the laakh which was previously poured in the compartments. The gaps between the stone and its mount is filled in by pressing pure gold strips. This detailing with gold is what makes this technique stand out.

GOLD STRIPS PRESSED IN MOUNTS

Kundan – Meena is not just a form of jewelery decoration but also a representative of our glorious past. It symbolises eternal beauty, wealth and power. This tradition has been passed down from one generation to another and it has the potential to go on for many more.





*The Author is a Colored Stone Graduate from Gemological Institute of America, Mumbai and a Diamond Graduate from Solitaire Diamond Institute, Bangalore. She also holds a Diploma in Jewelry Designing & Manufacturing from Jewelry Product Development Centre, Jaipur. She also blogs at 'The Jewel Affair'

*Picture Courtesy: Google Images


Monday 1 December 2014

Gemology Guide - Physical Properties of Gemstones

In the first chapter of SDI’s Gemology Guide we dealt with the cardinal virtues of a gemstone, now moving further we will explore the nature of these colorful and vibrant gems. In other words we will get to know about the properties of gemstones. The basic properties of gems have an extremely important bearing for not only who wish to study gemology but also for gem cutters, buyers and for people who deal in the gemstone markets. Properties of gemstones can be broadly classified into two: physical  and optical. Physical properties are determined most importantly by the crystal structure and chemical composition of a gemstone whereas the optical properties are dependent on various other factors along with the crystal structure.
This post will talk about the physical properties of a gemstone.

First and foremost, to have a crystal clear understanding of a gem’s physical properties it is required to be acquainted with what is a crystal structure of a gem. Each and every gem whether organic or inorganic is made up of atoms. These atoms are the basic building blocks for any gem. Now, almost all the gems are  inorganic minerals and these minerals always grow in a specific order termed as the crystalline structure. The regular, repeating arrangement of the atoms determine the crystal structure. The symmetry of the arrangement of atoms defines the outer shape of the gem crystal.  The crystal structure affects various properties of a gem like hardness, cleavage, fracture, specific gravity etc.

AMETHYST CRYSTALS

There are certain organic gems like opal and amber which are also made up of atoms but these atoms lack a systematic arrangement. Hence these gems are called amorphous gems.

OPAL-AMORPHOUS GEM

Certain factors like heat, pressure, space for crystal growth, chemicals available in the growing environment, cooling time etc, hugely affect the growth of crystals. These are basic requirements for gem crystals to grow. In any case if these requirements are not met it can lead to distortion in the growth. The atoms can get arranged in random patterns, when this happens aggregate gems are formed.

JADE-AGGREGATE GEM

Classic example of this is Amethyst which belongs to Quartz group and chalcedony which also belongs to the same group. Amethyst is a well formed crystal of the quartz group whereas chalcedony is an aggregate gem which results from disturbance which is caused  in the growth process of a crystal.

There are seven basic crystal systems in which the gem crystals grow.
Cubic – eg. Diamond, spinel, garnet etc.
Tetragonal – eg. Zircon
Hexagonal – eg. Berly and apatite
Trigonal – eg. Corundum, quartz, tourmaline
Orthorhombic – eg. Topaz, iolite, tanzanite, chrysoberyl, peridot
Monolinic – eg. Kunzite spodumene, moonstone orthoclase feldspar
Triclinc – eg. Amazonite, rhodonite,turquoise.


PHYSICAL PROPERTIES
Hardness: one of the most important virtue of a gemstone is its durability. But what makes a gem durable? Hardness of a gem is what makes it durable. Hardness can be defined as the ability of a gem to resist scratches. This property is greatly dependent on the crystal structure and how strong is the bond between the atoms. Hardness is usually expressed through Mohs Scale wherein various minerals are listed and given a number depending on its ability to resist scratches. This scale is based on the concept that a hard mineral can scratch another softer mineral. For example quartz can be easily scratched by corundum.

MOHS SCALE
(top to bottom – hard to soft)
10. Diamond
 9. Corundum
 8. Topaz
 7. Quartz
 6. Orthoclase Feldspar
 5. Apatite
 4. Fluorite
 3. Calcite
 2. Gypsum
 1. Talc

Toughness/Tenacity: This property is often confused with hardness but these are two different concepts altogether. Toughness is the ability of gemstone to withstand breaking and chipping. In other words how well can a gem take physical stress. Aggregate stones like jade and nephrite are excellent examples of tough stones. Topaz on the other hand is a very brittle stone.

Cleavage: it is a characteristic manner in which a gem breaks when an external force or stress is applied to it. Usually the break comes parallel to the area wherein the bond between the atoms is weak. This break creates smooth flat surfaces along the plane of atomic weakness.
CLEAVAGE

Parting: for one to understand what is parting in a gem, it is required to understand the concept of twinning. Sometimes during the growth of a crystal, the internal arrangement of atoms is disturbed. This disturbance is caused by certain changes in the growing atmosphere of the crystal. This leads to a change in the growth direction of the crystal forming twins. This process is termed as twinning and the location where the direction of growth changes it is called as twinning plane.
Twinning might take place not only when the crystals are growing but even after that due to metamorphic pressure.
When a gem breaks in a direction which is parallel to the twinning plane, it is termed as parting.
 
CONTACT TWINNING

CYCLIC TWINNING

LAMELLAR TWINNING

PENETRATION TWINNING


Fracture: besides cleavage and parting, any other break in a gem is called a fracture. Most transparent gems break in a typical pattern creating circular and concave ridges. This is called conchoidal fracture. There are other kinds of fractures as well splintery, granular, sub-conchoidal etc.
 
CONCHOIDAL FRACTURE

Specific Gravity: it is the measurement of density of a mineral. Two minerals of the same size  might weigh differently due to the variation in the density of minerals. Specific gravity can be described as a ratio between the weight of the mineral in air to the difference of  the weight of mineral in air and mineral in water.
In other words SG= wt. of mineral in air/ wt. of mineral in air – wt. of     mineral in water.
SG is a very important tool in gem identification.

Properties of gemstones is an imperative subject of gemology. It is a vital aspect which not only aids one in understanding the very nature of gems but also is of significant help to gemstone facet-ors. Along with these, it also gives crucial hints which can help one take good care of their gems.





*The Author is a Colored Stone Graduate from Gemological Institute of America, Mumbai and a Diamond Graduate from Solitaire Diamond Institute, Bangalore. She also holds a Diploma in Jewelry Designing & Manufacturing from Jewelry Product Development Centre, Jaipur. She also blogs at 'The Jewel Affair'.

*Picture Courtesy: Google Images