While many of the basics of how to buy a diamond apply to all diamond types, they vary a bit among the different colours. Since yellow diamonds are the most commonly known and popular among coloured diamonds, you need to consider some important factors to make a good investment.
What Are Yellow Diamonds?
Diamonds within the normal colour range are graded on a scale from D to Z developed by the Gemological Institute of America (GIA), with D being the most colourless and Z containing yellow, brown or any other tint noticeable to the naked eye. At a certain point, below the grade “Z”, the diamond colour stops looking like a faded shade and becomes a beautiful colour when the stone is viewed in the face-up position. This is the point when a diamond is considered to be fancy yellow.
The cause of each diamond’s colour is different. In terms of yellow diamonds, it is the presence of nitrogen molecules within the diamond’s crystal structure which absorb blue light and show yellow in return. Depending on the amount of nitrogen, yellow diamonds range from light to dark.
Natural yellow diamonds are the second most common stones of the fancy colour diamond family, with brown being the most common. Remarkably, yellow diamonds are found throughout the world, and they are not unique to a specific geographic area.
Evaluating the Colour of Yellow Diamonds
Yellow diamonds are classified using the following grades: Fancy Light, Fancy, Fancy Intense, Fancy Vivid, Fancy Deep and Fancy Dark. In the case of yellow diamonds, there are no Faint, Very Light and Light varieties. Instead, these are referred to as cape diamonds (diamonds from the lower end of the D-Z colour scale). The name originates from Cape Province in South Africa, where they were originally mined.
The colour evaluation of yellow diamonds has three main components: hue, saturation and tone.
Hue is the visible colour of a diamond, and the primary hue of yellow diamonds is yellow. However, most yellow diamonds are found with at least traces of modifying secondary hues, which are also included in the grade and greatly affect the value of stones. The most common secondary hues present in yellow diamonds are green, orange and brown. Secondary hues that enhance the primary hue or do not detract from it usually add value. For example, yellow diamonds with orangy secondary hues command higher prices than diamonds with greenish hues.
Pure yellow diamonds with no secondary hues, also known as canary diamonds or canary yellow diamonds, are more desirable; however, they are rare to find and command higher prices.
Saturation refers to the intensity of the colour. As a general rule, the more saturated the colour of a diamond, the more valuable it is. That is why diamonds that have pale or faint yellow colour are less desirable than those with deep and vivid colour.
Tone refers to how light or dark the colour is. The choice of the tone depends on your personal preference; however, the stones somewhere in the middle are the most sought-after.
Evaluating the Clarity of Yellow Diamonds
The clarity of yellow diamonds is graded the same way as that of colourless stones. The fewer inclusions, the higher the clarity grade. Yellow diamonds are known to be found in nature with relatively high clarity grade. No wonder flawless yellow diamonds are more expensive, but clarity is not crucial for fancy colour diamonds because flaws tend to be less visible due to the stone’s colouring.
When choosing the clarity of yellow diamonds, look for a stone that is eye clean, meaning the diamond should not have inclusions visible to the naked eye. Yellow diamonds in the SI1 – SI2 clarity range may look stunning and do not differ significantly from diamonds in VS or even the VVS range.
Evaluating the Cut of Yellow Diamonds
The cut quality of yellow diamonds, and all fancy colour diamonds in general, is not graded the same way as it is for colourless stones. Unlike colourless diamonds, fancy coloured diamonds are not cut to maximize fire, brilliance and scintillation. These characteristics are considered to be secondary. Colour diamonds are cut to maximize colour intensity which results in higher prices.
Keep in mind that an excellent cut yellow diamond costs a premium, so when choosing one, it is better to focus on the stone’s hue, saturation and tone and not judge the diamond using traditional cut grades.
Yellow Diamond Rarity and Prices
Natural coloured diamonds are extremely rare. Only 1 out of 10,000 carats is a fancy diamond. However, within the niche of coloured diamonds, yellows are the second most common, with brown diamonds being the most common.
Evaluating the price of a coloured diamond requires extreme expertise. When grading yellow diamonds, the first thing you will look at is the colour. Since there are hundreds of colour combinations, the price differences between them are vast. For example, the existence of a brownish tint in a yellow diamond will reduce its price, while green or orange will increase it dramatically. Besides, the stronger the yellow colour, the higher the price.
Fancy Intense yellow diamonds are the most sought-after yellows. Their yellow shade is very pure, and the price is usually 25 – 50% higher than for Fancy yellows.
Fancy Vivid yellow diamonds are even rarer and shine like very few diamonds. This makes them twice the price of an Intense Yellow and three times the price of a Fancy Yellow. There is a small group of vivid yellow diamonds that are even more valued. These are vivid yellow diamonds that come from the Zimmi mine in Sierra Leone.
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