Diamonds….why do the values fluctuate so much you ask ?
One of the biggest decisions in purchasing a piece of diamond set Jewellery is what to spend, you ask yourself what is actually reasonable to expect as a price, and why does the cost of pieces vary so much  ?
In 30 years of custom making Jewellery I have faced this question countless times, the short answer is simple, quality of stone dictates the price when we are talking about Diamonds. That is the SIMPLE answer, the proper answer however needs a little more explaining.
Many of you may know about the 4 C’s when it comes to Diamond quality, but there is a little bit more involved. I’ll endeavour to explain simply the tricky aspects of Diamonds and the grading and eventual price of them.
A diamond’s proportions affect its light performance, which in turn affects its beauty and overall appeal. Diamonds with fine proportions, symmetry, and polish optimize their interaction with light, and have increased brightness, fire, and scintillation. 
So in short we grade CUT the following way.
Excellent, Very Good, Good, Fair and Poor. The better the CUT the better the light play and as a consequence the brilliance reflected back to you.
Diamonds are graded on how closely they approach a colourless state, the less colour the higher the value. Our colour scale starts at D and drops through the scale alphabetically, introducing colour changes as it goes. The distinctions from one grade to the following are very subtle and can be difficult to detect to the untrained eye, however they make a considerable difference in the value of the stone.
Inclusions, imperfections, blemishes, call them what you will, it is extremely rare to find a diamond that lacks any internal and/or external characteristics. These characteristics are a by-product of its formation and are like a fingerprint, each totally different but with a consistency that allows us to grade them as the chart above outlines, again as with the other C’s the better the grading the higher the value of the individual stone.
Carat weight is the measurement of how much a Diamond weighs, not the physical measurement across it’s diametre but it’s actual weight. A metric Carat is defined as 200 milligrams and for diamonds under one carat each carat is divided into 100 points – similar to cents in a dollar or the decimal scale. 0.75 ct. = 75 points, 1/2 ct. = 50 points. 
So basing on the realisation the 4 C’s can mix and match numerous ways, it’s easier to understand the variation in Diamond prices across the board…
As an example you may be presented with a Diamond with the following specifications…
Carat – 0.60ct
Colour – G
Clarity – Slightly Included
Cut – Excellent

Against a Diamond exhibiting the following…
Carat – 0.90ct 
Colour – L
Clarity – Included3
Cut – Poor
The second Diamond is larger, by a long way, but due to the reduced grading on the other 3 C’s it will be considerably cheaper. This is the fundamental reason for Diamond pricing, when purchasing an Engagement or Diamond set Wedding Ring it’s of paramount importance than you ask these questions, you NEED to know the grade of your Diamonds, it is the only way you can feel secure in your purchase. My advice to clients is if the supplier can not or will not tell you the quality of the stones then walk away.
For further piece of mind, a Diamond report or Certificate is a great way to alleviate any worries you may have, ask your supplier for a Diamond that is certified prior to purchase, they can cost a little more but it is well worth it. There are many independent graders that will outline the Diamonds characteristics in a similar way to the image below, this happens to be a G.I.A report, certainly one the of the world leading graders, we endeavour to supply these certificates with all our custom made Engagement Rings.

For all your questions about Diamonds and Custom Jewellery – speak to