Diamond facts

Every diamond is unique. They come in many sizes, shapes, colours, and rarity which make them valuable.

Diamonds are harder than any other substance being composed of pure carbon. Most diamonds used as gemstones are colourless or lightly coloured. The only thing that can scratch a diamond is another diamond! 

The most important characteristics when choosing a diamond is to understand four C’s – these are Diamond Cut, Colour, Clarity, and Carat Weight these are what truly identify the rarity and value of a diamond. 

Making a smart diamond purchase is having confidence in your jeweller. Sherrington’s Jewellers will give you that re-assurance of your diamond purchase that meets your criteria and budget so your puchase will last a lifetime.

The Four C’s of Diamonds


Most diamonds have a presence of inclusions. Whether they are noticeable to the naked eye or under a loupe, nature has ensured that each diamond is as individual as the person who wears it.Appointment bookings available along with the service of a free measure and quote upon request.


The colour clarifies the degree to which a diamond is colourless, graded with a chart developed by GIA (Gemological institution of America), using letters, starting from D (colourless) to Z. The color evaluation of most gem-quality diamonds is based on the absence of colour.


Carat refers to the weight of a diamond. Larger sized diamonds are found less frequently in mines, giving them a greater value.


Cut is the biggest indicator of beauty and should be made a priority over the other C’s. With suitable proportions and angles, a diamond’s true brilliance and fire may be revealed.

The Kimberley Process is a joint government, international diamond industry and civil society initiative to stem the flow of conflict diamonds – rough diamonds that are used by rebel movements to finance wars against legitimate governments. The trade in these illicit stones has contributed to devastating conflicts in countries such as Angola, the Democratic Republic of Congo and Sierra Leone. The Kimberley Process Certification Scheme is an innovative, voluntary system that imposes extensive requirements on Participants to certify that shipments of rough diamonds are free from conflict diamonds. The Kimberley Process is composed of at least forty-three Participants countries, including New Zealand. Kimberley Process Participants account for approximately 99.8% of the global production of rough diamonds.

New Zealand has restricted rough diamond imports since January 12th 2005, in order to implement the Kimberley Process certificate scheme and reduce the trade conflict diamonds. Any rough diamonds without a Kimberley Process certificate will be seized at the border and their importer could face prosecution according to the New Zealand Customs Service. Imports of rough diamonds into New Zealand are very small.

For further information on the Kimberley Process please visit the World Diamond Council