Jewellers & Watchmakers of New Zealand Inc.
021 59 69 88
Member login

Search a Member


Search by Company


What you should know about Diamonds


Thinking about buying a diamond?
If you are thinking of buying a diamond, you are about to enter an enchanted world of romance, intrigue, legend and history. Indeed, it was said that Cupid's arrows were tipped with diamonds. The Ancient Greeks believed that diamonds were splinters of stars that fell to earth, and some said they were the tears of the Gods. Diamonds have been sought after, fought over and even worshipped, so it is appropriate they have become the ultimate gift of love.

Why a diamond?
The reasons for buying a diamond are as diverse as the people who desire them. Diamonds are beautiful: Formed millions of years ago, they have stood the test of time with a fire and brilliance that is unquenchable. They create an aura of success and inspire feelings of pride. Diamonds are durable: A diamond is the hardest natural substance known. They resist deterioration and you can be confident that the diamond you buy today will still shine as brilliantly when your great-grandchildren wear it. Diamonds are rare: For every carat of rough diamonds recovered, more than 250 tonnes of ore have to be blasted, crushed and processed. Only 20% will be of gem quality.

Choosing a diamond
Two diamonds may at first glance look alike, but the truth is that they are very different. Although they may be of equal size, they may have very unequal values.

There are four characteristics to understand that will help you when buying a diamond. They are known as the four C's - cut, colour, clarity and carat weight. It is the combination of these four factors that determines the value of a diamond.

Colour: Most gem diamonds seen alone appear white, but most have a hint of colour, mainly yellow. Diamonds with no trace of colour at all are extremely rare and the closer they are to no colour, the more rare and valuable they will be. Also rare are diamonds with a strong pure colour that are called "fancies" and which are very valuable. The Argyle Mine in Australia, which is the world's biggest diamond mine, produces the rare pink diamonds as well as beautiful cognac and champagne coloured diamonds.

Clarity: Diamonds were formed millions of years ago, deep within the earth under enormous heat and pressure. Consequently, most diamonds contain tiny marks, known as inclusions, which make each stone unique. The inclusions don't necessarily weaken the stone and when they don't interfere with the passage of light they do not affect its beauty. The fewer and smaller the inclusions, the more valuable a diamond will be.

Cut/make: How well it is cut determines a diamond's brilliance. It is the skill of the cutter that unlocks the natural beauty of a diamond, revealing all of its hidden fire and brilliance. Most diamonds are cut with a full 58 facets and it is important that these are cut to precise angles. A diamond that is cut well will reflect light from one facet to another and then back out through the top of the diamond. Only a well-cut diamond will really sparkle.

Carat weight: A diamond's weight is the simplest of its characteristics to measure and from the earliest times it was used to calculate a diamond's value. Diamond weight is measured in carats, and each carat is divided into 100 points A carat is equal to one-fifth of a gram.

How much should I spend on a diamond engagement ring?
All that a diamond engagement ring symbolises is priceless. But you have to be practical. So, how much should you spend on this significant purchase? Today, two month's salary is generally considered to be a good guideline. Planning a wedding can be an expensive time, but remember that costly receptions and honeymoons quickly become a memory and fairytale wedding dresses will be worn once and then quickly fade. However, a diamond will be with you forever and will be a constant sparkling reflection of your love for each other.

How to care for your diamond and its setting
Diamonds need care to keep them at their brilliant best. A clean diamond reflects light better than one that has been dulled by skin oils, soap, cosmetics and grease. So it is important to clean your diamonds regularly.

Your JWNZ jeweller is the best person to do this. The setting can be checked at the same time. However; it is also possible to clean your diamonds at home with a commercial jewellery cleaner or a diluted mixture of ammonia, detergent and warm water. Soak the diamond in the solution (the dirtier it is, the longer it will need) and then scrub gently with a soft brush. Making sure the plug is in the sink, rinse well with water; and dry with a soft lint free cloth.

Do not wear your diamond ring while doing rough work and don't let your diamond jewellery come into contact with chemicals as the setting may pit or discolour.

It is advisable to take your jewellery for a professional clean and polish every year so your JWNZ jeweller can check the settings for wear. Appraisal updates should be obtained every two or three years from a qualified, registered appraiser.

Different settings for your diamond
Bezel Set: Diamond set in a sleeve of gold, rubbed over all the way around. Channel Set: A diamond set in a row with a strip of gold either side to hold the diamonds in place. Claw Set: A diamond set with each claw bent over to secure the Stone. Pave/Grain Set: Diamonds set close together; held in place with grains of gold.

Treated diamonds
There are a number of ways in which diamonds can be "treated". Care should be taken when repairing any jewellery containing treated diamonds. If you know the diamond is treated, tell the jeweller!

Laser drilled: The drilling literally "burns" out an inclusion. Can sometimes be seen as a fine line or tube.
Fracture filled: Surface reaching inclusions (cracks or "feathers") are filled with a "glass" type substance close to the refractive index of a diamond. The filling lessens the ability to see the inclusions. Laser drilled diamonds are sometimes filled in similar fashion. The filling can sometimes be detected as a faint mauve or other coloured 'flash" under magnification and special lighting conditions.
Irradiated: Artificially coloured by electron bombardment then treated by heat or other methods to bring to the desired colour removing any residual radiation. The colouration is permanent and typically includes green, blue and yellow.

Why you should buy your diamonds from a JWNZ jeweller
Knowledge of the diamond industry and the nature of diamonds requires years of extensive study. Therefore, it is absolutely vital that you purchase your diamond from a reputable jeweller, one that you can trust.

  • Established jewellers prize their good reputation.
  •  It is important to know the company you are dealing with. Ask questions. Be confident of returning for advice and service in the future.
  • A JWNZ jeweller can explain why diamonds that appear to be virtually identical may show a wide range of value.
  • You can be assured of professional service and specialist, honest advice.