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What is gemmology?

Gemmology is a science that is concerned with gemstones and other materials used for personal adornment or objet d’art. It is a scientific discipline that has evolved from mineralogy — a branch of geology.

Twenty-first century gemmology involves the scientific study of gemstones (diamond, ruby, sapphire, emerald etc), ornamental materials (lapis lazuli, malachite), biological gem materials (amber, coral, ivory), and their synthetic counterparts as well as imitations. These materials must be identified and discriminated using a combination of established scientific fact, specialised gem testing instruments, and a comprehensive range of gem testing techniques. With advances in technology the academic and practical challenges being offered to the working gemmologist are ever increasing.

Although many people may not have heard of gemmology, it is not a new science. Long before The Gemmological Association of Australia was formed (in 1945) the world’s scientists were fascinated by the special properties possessed by gemstones.

For millennia, civilised man has been captivated by the beauty, mystery, rarity and value of what soon became known as (precious) gemstones. These much sought after objects of beauty and desire included diamond, ruby, sapphire, emerald, and pearl. While the adjectives precious and semi-precious are no longer used by gemmologists, today over 150 special minerals that posses the desirable attributes of beauty, rarity, and durability are termed gemstones. It is the scientific study of these very special minerals that forms the basis of the science of gemmology.

Over recent years ever-inventive man has duplicated many of Nature’s masterpieces, and in the process created precise man-made duplicates (synthetics) and very effective look-alikes (imitations). In addition, numerous techniques have been discovered for artificially enhancing the beauty of lower quality gemstones. The identification of these offers a continuing challenge to gemmology and gemmologists.

Gemmology is a science that is expanding at an exponential rate. If you wish to undertake the challenge of learning and understanding the science of gemmology, then The Gemmological Association of Australia’s courses in gemmology are for you.


What is a gemstone?

By modern definition, a gemstone is a mineral or other natural material that is beautiful enough, durable enough, and rare enough, to be used for personal adornment or for the embellishment of personal possessions.

Most gemstones are rather rare minerals. They are naturally occurring inorganic crystalline elements or compounds that have chemical compositions and physical properties that are fixed or may vary between very fixed limits. Gemstones display the desirable attributes of beauty, rarity, and durability.

Other materials, that are less commonly used for gem purposes include:

  • rocks, that are formed from mixtures of minerals e.g. lapis lazuli.
  • non crystalline materials e.g. amorphous opal.
  • ornamental materials (ornamentals) that are those minerals which due to their lack of transparency owe their beauty to their body colour and/or attractive pattern of colours e.g. malachite.
  • Biological (organic) gem materials, which are materials produced by living organisms e.g. ivory, amber, or precious coral.

With respect to gemstones:

1.     Most are single minerals, and not other materials.

2.     Of the more than 3,000 known minerals found in the earth, the gem minerals total about 150.

3.     Gem minerals are very minor constituents of the ‘living planet' known as planet Earth.

Today many gemstones are being value-enhanced by the application of various treatments to the gemstone or gemstone rough. Although the original materials may have a natural origin, man’s intervention has converted these materials into value-enhanced gemstones e.g. heat treated ruby and sapphire, ‘oiled’ emerald, irradiated coloured diamond, diffusion-treated sapphire.

In contrast, synthetics and imitations can not be described as gemstones; for essentially they are man-made. Therefore:

  • A synthetic or artificial gemstone is a man-made material having a chemical composition, crystal structure, and physical properties that are almost identical to those of a (natural) gemstone. e.g. synthetic sapphire, synthetic diamond.
  • Imitations are man-made (manufactured) products that only visually resemble the gemstone they are intended to simulate. e.g. glass, plastic, composite stones which are made from several components.


What are the Advantages of Gemmological Knowledge?

The key-word is knowledge … that is knowing.
At some stage in their life, almost every person buys or obtains a gemstone or at least one piece of gemstone-set jewellery. If you are aware of the differences between gemstones, value-enhanced gemstones, synthetics and imitations, then you know what you have and you will not be duped by value-enhanced gemstones, synthetics or imitations. If you are purchasing you can choose which you want.

There are many coloured stones which provide less expensive alternatives to the more expensive traditional gemstones of diamond, ruby, sapphire, and emerald. Do you know what coloured stones are available and what are their important characteristics? How often are these synthesised, imitated, or value-enhanced?

It you are a fossicker, or a lapidary, will you know whether you have found a piece of genuine rough gem stone, or perhaps a fragment of water-worn glass? If you facet gemstones, as a hobby or for profit, how and where will you learn how to correctly orient rough to achieve the best display of colour through the table of the gemstone you are about to facet?

For those who travel overseas, the opportunity to purchase gemstones cheaply in Asian countries must to be tempered by the knowledge of obvious pitfalls. That ‘bargain purchase’ often can let you down badly, if you return home only to discover that poor cutting has seriously undermined the value of your bargain gemstone, or even worse, you bought a synthetic or an imitation. Determining whether your bargain gemstone been value-enhanced is yet another challenge the tourist must overcome.

Factually, the more gemmological knowledge you can acquire, the more potential exists for its use.

Gemmologists come from every walk of life. The Gemmological Association of Australian has gemmologist members who are gem merchants, jewellers, geologists, antique dealers, doctors, dentists, pharmacists, librarians, shop assistants, secretaries, home makers … the list is endless.

Remember, the appeal of gemmology is universal. 


What is a gemmologist?

Gemmologists identify gemstones, ornamental materials, biological gem materials, and their synthetics (exact duplicates), imitations (look-alikes), and value-enhanced forms, and, as well, evaluate their quality. The gemmologist appreciates the desirable attributes that make gemstones — their beauty, rarity, and durability.

In their day-to-day work gemmologists may do any or all of the following tasks:

  • Identify near-colourless gemstones such as diamond, coloured stones, ornamental materials, rocks, and biological gem materials using a combination of visual observation, examination under magnification using the gemmologist’s 10x hand and the gemmologist’s binocular microscope, and a range of specialised gem testing instruments.
  • Discriminate natural gemstone’s from their man-made synthetics and imitations.
  • Identify and discriminate all value-enhanced and otherwise artificially treated gemstones, ornamental and biological gem materials.
  • Assess the quality of all gemstones and other gem materials.
  • Assess and quantify damage to gemstones and gem materials.
  • Assess a stone’s durability and suitability to a particular purpose.

Gemmology, the science of gemstones, requires that the gemmologist identify gemstones using his or her specialised knowledge and appropriate gem testing instruments.

Gemmologists usually work indoors, either independently or as employees of gem merchants, manufacturing jewellers, wholesale jewellers, or retail jewellers. At times gemmologists may be required to work under quite primitive conditions to identify and evaluate parcels of rough and cut gemstones that are offered for sale in often quite remote mining localities. It is indeed a fact that geologists and mining engineers who are also gemmologists are much in demand.

Gemmologists must have a basic love for gemstones, an inquiring mind, a reasonable academic ability, common sense, dedication, patience, a good memory, and a meticulous attention to detail.