Friday, 28 June 2013

Artical on World's Famous Diamond's- Part I


-Raunak Agarwal
Gemology Instructor, SDI

Although diamonds are found in many countries, some of them stand above all for their weight, shine, abnormal beauty, efficacy, lesser availability and divinity. Let us discuss them one by one.

  1. KOHINOOR: This 105 carat diamond once belonged to Rana Ranjit Sing of Punjab. It was purchased by the Shah of Iran in 1739 from the Raja with the help of the Britishers who had started spreading their wings in India then. Later it was procured by the East India Co. which presented it to Queen of England. It was later fixed in the crown of the Queen Mary. At present it is in the custody of London Tower. India Govt. has asked for the stone back, as it was taken forcefully.
    Kohinoor Diamond

    Queen Alexandra's Crown with Kohinoor Diamond
  2.  HOPE: The Hope originated from India in Golconda where it was mined at the Kollur mine. According to the legend the diamond was stolen from a statue of the Hindu goddess Sita. It weighed in rough 112 carets and was first known as the "Tavernier Blue"as it was aquired by Jean- Baptiste Tavernier (1605-1689), the French traveller and pioneer of jewellery and diamond trade with India. The French Blue was then passed from one ruling French King to the next until the French Revolution when it was stolen. What happened next was a bit of a mystery but in 1839 an entry of a fabulous Blue Diamond was entered in the gem collection catalog of Henry Philip Hope,the man from whom the diamond now takes its name. It passed through several owners before an American heiress named Mrs. Evalyn Walsh McLean brought it to the United States. She added its current setting- it is now surrounded by 16 white diamonds and hangs on a chain of 45 diamonds. It was said that "Bad Luck and Death not only for the owner of the diamond but for all who touched it". Possession of the Hope Diamond led to violent deaths, disaster and debt leading to stories, myths and legends of the Curse of the Hope Diamond. It is currently Housed in the Smithsonian National History Museum in the USA.
    Hope Diamond on Display at Smithsonian National History Museum
  3. SHAH: This 88.7 carat weighing diamond was also procured from Indian mine. It was very lightly polished. It changed hands many times and ultimatly reached the Shah of India and was retained by him for a long period. In 1829 the Shah presented it to Tsar Nicholas the First. At present it is lying in Kremlin (MOSCOE).
    Shah Diamond
  4. CULLINAN I: This 530.20 carat weighing diamond was cut, trimmed and polished from the 3106 carat weighing diamond, perhaps the heaviest diamond so far taken out. It has got its name from Sir Thomas Cullinan, the chairman of the main company. This diamond adorns London Tower at the present. It is also Star of Africa.
    Cullinan Diamond

    Sovereign's Royal Sceptre of the British Crown Jewels
  5. NASSAK: This diamond was looted by the Britishers from the Shiv Temple in Nassak in 1818. Then it weighing 43.38 carat. It was trimmed. At present it is owned by some Rich American.
    Nassak Diamond
  6. DRESDEN: It was acquired from a mine in India. This 41 carat diamond was bought by Duke Augusta in 1700. It is at present in the Green Hall of Dresden.
    Dresden Diamond
Sumptuous Hat Clasp


Various Internet Sources 


Saturday, 22 June 2013

A Little Insite into what Diamonds are and how its Formed...

What is a Diamond?

Madhuri Sarvothama
Diamond Grading and Gemology Instructor, SDI

Diamond is a mineral that is a crystalline form of carbon (latin: Carbo"Coal"). Like graphite, diamond's chemical composition is Carbon. The carbon atoms in diamond are arranged in tight three- dimensional patterns with strong bonds in all direction, which makes diamond the hardest natural substance and an ideal gem for everyday wear.

Diamond- Round Brilliant Cut

Different views of a Round Brilliant Cut

How are Diamonds Formed?

Diamonds form between 90 and 120 miles under the surface of the earth, deep beneath the continents. This is where ideal conditions for normal diamond formation can exist- a temperature range of 900 degrees Celsius to 1300 degrees Celsius and pressures between 45 to 60 kilobars more than the normal sea- level pressure. Diamonds form three in two types rocks called peridotite and eclogite. They may remain below the earth for billions of years until conditions within the earth's mantle and magma rapidly transports the already- formed diamonds from the mantle region to the surface of the earth, leaving carrot- shaped pipes. Then the diamonds that are not blasted onto the surface may stay in the pipes for millions of years before someone discovers them. the host rock of the diamonds in the pipe is Kimberlite or Lamproite.

Diamond in the Ore

               If the diamonds are found in and around the pipes then this kind of deposits are called primary deposits. And all other deposits are called secondary deposits. If  due to weathering conditions, diamonds were carried into neighboring rivers and streams, and even into the ocean. Since diamonds are heavy, they sink to the bottom when caught in small whirlpools. Deposits in rivers and streams are called alluvial deposits and often contain higher quality diamonds than primary deposits within a diamond pipe because the better ones are more likely to survive the water's tumbling action against rocks. If the diamonds reach the ocean, they are called marine deposits.        

RenĂ©e Newman, Diamond Handbook- a practical guide to diamond evaluation: completely  revised 2nd edition 


Friday, 14 June 2013

An Article on Gemstones



-Raunak Agarwal
Gemology Instructor, SDI

Synthetic Gems
Synthetic means "put together". A synthetic(or laboratory- grown) gem is made from the same raw materials as the natural gem.

It is optically and chemically identical to the natural gem, but it came from a lab.

 The drive for synthetic began when industrial diamonds were needed during World War II. It took years to develop industrial- grade diamonds, and years more to be able to manufacture stones of gem quality. Producing the early   gem- quality diamonds was more expensive than mining for natural diamonds. Improved technology brought down the price of synthetic diamonds.

 When a gem made of non- natural material is offered for sale, it is the seller's responsibility to inform the buyer that it is not a natural gemstone. This disclosure must be made at all levels of jewellery sales. Synthetic gems cost only a fraction of the price of natural gems.


Simulants are imitation gems, fabricated from such materials as glass, ceramic or plastic.  resemble the appearance of the gem it is mimicking, but it cannot duplicate the true gem's characteristic properties. Simulants have different physical and chemical properties. Some common simulants of diamonds are synthetic moissanite, CZ(cubic zirconium), YAG(yttrium aluminum garnet) GGG(gadolinium gallium garnet), strontium titanate and synthetic rutile.
 A gemologist can easily distinguish a real gem from a simulant by using appropriate lab equipments.

Are Certificates Necessary? 

It is always a good idea to insist on a gemological certificate. The extra assurance of a gemological certificate not only provides peace of mind, but it can be useful for insurance purposes and future resale also.

For some coloured stones, treatments greatly affects the value of the gem. For example, an untreated ruby is worth far more than a treated one, an untreated sapphire is far more valuable than from an enhanced one.

(SDI) Solitaire Diamond Institute Gems & Jewellery Lab provides certification services also.

The lab report comes with shape, measurements, colour, clarity, R.I, S.G, weight and determination as to whether the stone is natural or synthetic. It may also indicate whether the gem has been subjected to treatments.  
SDI Lab Certificate

SDI Lab Certificate

Various Internet Sources



Friday, 7 June 2013

A peek into Technology- CAD Jewellery Designing

Why CAD?

- Nagaraksha
CAD Instructor, SDI

How much has technology influenced our day to day activities? Have we ever thought of it? Can we imagine a life without a mobile, computer laptop, etc, "No, not at all". Technology is bringing revolution in almost all fields. So it is with our own jewellery designing and manufacturing sector also.

We have been blessed with the development of CAD (Computer Aided Designing). What is CAD? It is the use of computers for making 2D drawings and 3D models (jewellery piece). CAD is gradually getting popular amongst the designers prefer jewellery pieces designed in CAD. Why is it so?? There are 'n' number of reasons to be told.

The most important of all is the precision which can be achieved up to 100%. CAD designs are of high quality and light weight. CAD designing takes very minimal time. So, the overall designing and production time for a piece hardly takes time thus your piece reaches the market faster (profits also reach you faster.... for which we all work..)
A Wax Mold and A White Gold Cast

Looking in other way, one system can replace many people, reducing manpower. Less people at work means easy management, effective communication, reduced expenses and so on.
 CAD files can be accessed by anyone involved in the process, even those based in different offices across the globe. Additionally, files can be sent instantly with the help of the Internet. When compared to traditional methods which require someone to track down files, pull them from a file cabinet, package them, hire a courier, and then wait several days for the files to reach their destination.
A CAD rendered piece (Finger Ring) by Keerthi Shree, CAD Instructor, SDI

CAD systems can also have a built-in system for calculating the costs of manufacturing the design, including any materials used, separate components and additional items. The costumer can be provided with clear estimate of bespoken jewellery even before it is manufactured.

The above are very few out of the many benefits of CAD to the designer, jeweller and buyer.
CAD drafting will no doubt continue to evolve and become more powerful, and remain, as one of the most important technological developments for the manufacturer and the consumer.
A CAD rendered piece (brooch) by Keerthi Shree, CAD Instructor, SDI

Various Internet Sources

Monday, 3 June 2013

An Article on Carved Stones


- Keerthi Shree S
Jewellery and CADD Designing Instructor, SDI

Carved Gemstones are sculptural pieces that can be worn as jewels. Abundantly available in nature, these fascinating pieces blend the mystery of nature with the skin of man. The designed style in carved stones often replicate nature, from the colours of suitable tourmalines to stunning pink corals. It is refreshing to perceive a free form carved piece of gem in jewellery than the faceted gem or cabochon. Diamond accent can elevate carved gem into the high- end jewellery. carved gemstones are of two kinds- A Cameo and Intaglio. Carving in intaglio, with the design projecting out of the background as in nearly all cameos, are also covered by the term.
A Jewellery from Victorian Era

The earliest engraved gemstone were the Egyptian scarab, carved to resemble a beetal, an intaglio; a flat gem with a image carved in relief above the planar surface. in Middle Ages, Mediterranean coral was used in religious beads and small carving and cameos. It was traded along ancient silk routs between Europe, Egypt and China as early as 100 B.C. Traders offered corals in exchange for silk, spice, porcelain and lacquer in the far Eastern and for many products from Africa.Superstition was not far behind either. Cameos of  legends like Alexander The Great, were said to possess magical powers and were often used by people as totems over the period of time.
A Manually Designed Cameo Jewellery Set

Women now a days are wearing jewellery to match the latest colour or style in fashion. This artistic creation would attract those who appreciate beauty.

What makes a gemstone unique to carving and faceting? Well, it is the toughness and hardness of the stones. It is their innate capability of their composition that makes them fit for carving or faceting. "In the case of minerals and gemstones, hardness refers first to scratch hardness, then to cutting resistance."Toughness on the other hand, "is its ability to resist being fractured".

There are various types of gemstones that are carved, the list encompasses coral, ivory, lapis lazuli, horn, amber, jade, amethyst, agate, onyx, spinel, shell and jets. These gemstones hold this prestigious podium because of their toughness quality. Thus, the list is selective and exclusive. The carved gemstones were expensive because of the high quality materials, the complexity of the design and the labour involved. The setting are most often inspired by the stone's shape and colour and by the mechanical constrained of carving. Sometimes it is a challenge to set stones that have very unusual shape. Today, the joy of wearing a beautiful carved gemstone jewellery piece is as great as ever.
An Intaglio ring
This type of jewellery's typical features may signify sized carved gemstone set on interesting assortment that can look very fancy and exquisite. Carved gemstone in fun shades and styles can be worn as necklace, earring, rings and bracelets.

Carved gemstone offer designers with creative versatility, these are accessible in shapes such as carved hearts, leaves, flowers and beads. Interesting designs combining carved and faceted gemstone created an exciting juxtaposition. These certainly set the stage for a contemporary and elegant look.

A Manually Designed Cameo Pendant


Peltason, Ruth; Living Jewels- Masterpieces from Nature; The Vendome Press, 2010

Schumann, Walter; Gemstones of the World; The Sterling Press; revised edition of 1976