Buying a diamond engagement ring is not only a big emotional commitment but a significant financial one for most couples. While the internet is usually a great tool for conducting some initial research before buying a diamond, it can become difficult when you need to make a price comparison. The key piece of advice that i give my clients is – Don’t believe everything the diamond certificate tells you. After all it is only an opinion, graded by humans, who as we all know are prone to mistakes.
Buying a Diamond Tips
1. Certificate type
While the GIA is considered one of the most renown independant certificate on the market, there are some certificates that are really not worth the paper they are written on. Some are consistently at least one colour grade and clarity grade out. (to the downside) So while it might seem cheap on face value, it isn’t when you compare what you are actually getting for your money.
2. Excellent cut grade – What does that mean ?
It used to be that approximately the top 20% of stones received an excellent cut grade, today this figure is probably closer to the top 40%, as the parameters for an excellent cut grade are widening. The diamond grading laboratories like Google won’t tell you when they move them. You just need to know exactly what a perfect cut diamond looks like. Where you sit in this spectrum will not only be seen in the brilliance of the stone but the price as well. Make sure that when you are buying a diamond you don’t pay for a top 10% cut grade stone, when you are actually getting a top 30%.
Buying a Diamond Tip – Never buy a diamond with a table facet greater than 60%
3. Independently check your colour grade.
Colour grading can be affected by so many variables. How tired was the diamond grader at the time and things like excess coffee can all affect the way we perceive colour. The margin for error is so small, that it only takes a small error to cost you thousands depending on the size of diamond you are looking at. Make sure your diamond is checked by a qualified diamond grader. The colour on the left is an F colour and the one on the right is a H colour. 
4. Clarity grade – inclusion location
If you were deciding between two diamonds – one with an inclusion in the middle of the stone or one with a mark on the edge of the stone (that can be covered) i am sure you would choose the one on the edge. It is for this reason the diamonds with marks in the middle (table facet) are discounted and made cheaper. When buying a diamond always aim to have a girdle (edge) inclusion.
5. Fluorescence
A little understood characteristic. Basicly it is the way the diamond responds under ultraviolet light (like the one in discos). Anything slight to nill is ideal. Some medium fluorescent stones can be ok, but you really need to be careful as they can sometimes make the diamond look cloudy (which reduces the brilliance). Strong fluorescent stones are to be avoided – and they are much cheaper.
Buying a Diamond Tip – Never buy strongly fluorescent diamonds
6. Laser inscription
This is a little be a nice to have – not need to have. The inscription is only on the surface of the stone. If someone wanted to, it is possible to have it polished off by a diamond cutter. So don’t discard a beautiful stone just because a stone doesn’t have a laser inscription
7. Not consulting a diamond expert
For complete piece of mind, it is always important to see a diamond expert when buying a diamond. You wouldn’t take your car to be serviced to someone that just sold tyers ? Like jewellery there are some who specialise in diamonds and some that just sell general jewellery. A diamond specialist will not only be able to tell you why a diamond is a better quality but be able to show you and answer any question you have about your diamond. 
At the end of the day, unless you want to look at your diamond certificate on the anniversary of your purchase every year, the diamond paper is not as important as finding the most brilliant diamond.
If you have found this helpful or have something you would like me to answer, please email me directly and i will answer any question that you have.