BUDGET

You don’t need to get the highest quality diamond to get something that is of equal beauty. The price will vary depending on the quality of diamonds in the market, the source of the diamond and where if was manufactured.

CARAT

Carat is a diamond’s weight, not its size – how large a diamond appears is also dictated by other factors such as shape and cut proportions – the following guide shows the approximate correlation between carat weight and size for all the diamond shapes.

Fergus James Top Tips

1. Buying a 0.9ct diamond, as opposed to a 1ct diamond only reduces size measurements by around 5% but reduces the price by around 25%
2. With round diamonds pay extra attention to the cut – Fergus James recommends excellent cut for round diamonds - with fancy shapes (all the other shapes) pay attention to the actual measurements (in mm) outlined on the diamonds GIA certificate.
3. Diamond prices increase disproportionately when you reach the half and full carat mark (eg 0.50ct – 1.00ct – 1.50ct – 2.00ct, etc). The value lies just below these measurements.

COLOUR

The colour scale measures very subtle variances in the shade of a diamond.  D has zero colour shade (perfectly white) whilst Z has a yellow/brownish tinge.  The way a colour appears visually in a diamond depends upon the diamond shape as well has the cut and the ring setting

Fergus James Top Tips

• Round Diamonds are the best at hiding colour
• Big Brands - Cartier generally use D-F - whilst Tiffany generally use D-I colour 
• Fancy Shape - fancy shapes show colour more than round diamonds
• Diamond size - the larger the diamond the more the colour shade shows
• Halo Ring Designs - select D-G colour for halo ring designs as the colour shows more in this design
• Visual appearance - D-F colors look identical to the naked eye but the price typically varies considerably

If you are unsure contact the Fergus James team for practical guidance - CONTACT

CLARITY

Clarity is the measurement of natural inclusions found within the diamond. Every diamond, with the exception of Flawless and Internally Flawless diamonds, have inclusions to a great or lesser degree. Some inclusions are visible to the naked eye but most are not. The shape, size and position of the inclusions, as well as the shape and size of the diamond, all contribute. If the inclusions in a diamond cannot be seen with the naked eye they are referred to as being “eye clean”. From a practical point of view, there is no visual day-to-day difference between an eye clean SI1 and a flawless diamond.

Fergus James Top Tips

For Brilliant-Cut diamonds, especially Round shape, you can typically find eye clean diamonds in the “SI” range and easily within the VS bracket - our curation team are experts at finding a clean stone so contact us for advice and options.

For Step-Cut diamonds (Emerald and Asscher shapes) you’re best to stick to VS1 or the VVS range to ensure they are 100% eye clean.

If you find something you are unsure about we are simply a message away! Remember our curation team inspects every single diamond, so beauty is guaranteed!

CUT

The cut only applies to round diamonds and has the biggest impact on the overall beauty, sparkle and appearance of the diamond. The cut is the most important aspect of the selection process. The better the cut the more the diamond sparkles. The GIA only measures ‘cut’ for round diamonds, not fancy shapes (all other shapes such as oval, pear cushion etc).

Fergus James Top Tips

• Round Shape - for maximum sparkle select an excellent cut
• Appearance - excellent cut diamonds appear larger than vg cut diamonds
• Fancy Shape - Focus on diameter and proportions to maximize appearance
• Contact - for fancy shapes we recommend you contact our team for help and advice

FLUORESCENCE

Fluorescence refers to the glow of a diamond when seen under intense UV Light.

Fergus James Top Tips

Fergus James subscribes to GIA’s view on Fluorescence; where it is regarded as neither a good or bad aspect but is purely down to personal preference. If you are looking for value, strong or medium will work for you. If it feels wrong for you, then aim for faint or none.

The main myth surrounding Fluorescence is that diamonds with higher Fluorescence are milky which is incorrect - milkiness can be found in diamonds with and without fluorescence!

Day to Day, Fluorescence is not visible.

SYMMETRY

Symmetry refers to the precision of how a diamonds facets align as well as how it interacts with light.

Fergus James Top Tips

Based on years of practical experience, Fergus’ top tip is to stick within the Excellent to Very Good range for symmetry, there is no visual difference between Excellent and Very Good. So don’t let an otherwise perfect stone go if the symmetry is Very Good. If seeking perfection, we would always recommend to look for a diamond with ‘Excellent’ symmetry in order to optimise the diamonds fire and brilliance.

POLISH

Polish refers to the final finish of a diamond used to smoothen out a diamonds facets to achieve a glass like surface. GIA examines all diamonds under 10x magnification to grade the diamonds final polish features ranging from excellent to poor.

Fergus James Top Tips

Based on years of practical experience, Fergus’ top tip is to stick within the Excellent to Very Good range for polish, there is no visual difference between Excellent and Very Good. So don’t let an otherwise perfect stone go if the polish is Very Good.

CERTIFICATE

Diamond certificates are issued to confirm a stone’s technical characteristics, value and identity. The GIA (The Gemological Institute of America) have set the worldwide standards in diamond grading since 1931 and have continued to lead the grading standards since. For example, when GIA grades a diamond as a D then the diamond is a D. When other institutes grade a diamond as a D colour, the GIA may not consider the diamond as a D as it may not be measured to the same standards as the GIA.

Fergus James Top Tips

All diamonds at Fergus James are GIA certified diamonds, this is so we can ensure we’re giving our customers the very best according to international standards set by GIA.