The Gemmologists

The Laboratory Gemmologist

When acquiring coloured diamonds and precious gemstones it is important to understand that a laboratory gemmologist is the most highly trained scientist in the field of gemmology. The laboratory gemmologist not only assesses and certifies diamonds and precious gemstones but is also instrumental in developing analytical tools and technology to detect artificial enhancements of stones which may appear in the marketplace.

Other Levels of Gemmology Training

All participants in the precious gem and fine jewellery field require some education or training in gemmology in order to carry out their profession or trade.

The Jeweller

Requires some training in gemmology to ensure their clients are receiving the quality promised during the sale process. Most jewellers are not gemmologists and do not have a gem lab in their place of business. While some gemmologists may be jewellers, the opposite is not necessarilty true.

The Lapidist or Gem Cutter

Requires some training in gemmology to understand the structural integrity of various types of gemstones such as fracture lines and inclusions. To avoid damage, the stones needs to be properly examined before cutting and polishing.

The Jewellery Designer and Manufacturer

Requires some training in gemmology to understand the structural limitations of gemstones. This will ensure the appropriate selection of settings for each gemstone and the understanding of what processes or tratments might damage the gemstone.

Criteria Used in Assessing Gemstones

Refractive Index

Each type of gemstone refracts light in a very specific way. This can be used to establish the type of gemstone.


How a gemstone absorbs light is another factor in determining its colour, quality and type.

Relative Density or Specific Gravity

Each type of gemstone will respond a certain way when weighed in both traditional scales and in water. This density is another important tool in determining the type of gemstone.