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Diamond Guidance

Diamonds are one of the most cherished and sought-after gemstones, renowned for their timeless beauty and symbol of love and commitment. Buying diamonds is a significant investment, so it’s essential to educate yourself, ask questions, and purchase from reputable and trusted sources.

From exploring the basics of diamond quality, available shapes and cuts to delving beyond the 4 Cs and how these impact your diamond’s appearance, this guide will allow you to make a confident and informed decision when selecting a diamond for your most treasured piece of jewellery.

Every diamond in the world is unique. Below is the anatomy of a diamond to help you understand the terminology that describes a diamond’s features.

Table: The largest facet of a diamond or gemstone. It’s usually the surface area at the very top of the stone.

Crown: This is the top section of a diamond, where the girdle joins the table.

Pavilion: The pavilion is the bottom part of the diamond that connects the girdle to the culet. A pavillion that is too shallow or deep will result in light escaping from the side or bottom of the stone, as opposed to the desired finish of light reflecting out from the top of the stone.

Girdle: The girdle sits between the crown and the pavillion and defines the perimeter of the diamond. We recommend a ‘medium to slightly thick’ girdle. Thick girdles are undesirable because they add additional weight to the stone, without increasing the appearance of the stone size. A thin girdle makes the diamond more susceptible to damage.

Culet: A small facet at the bottom end of the gemstone, often ending in a tip or point.

Depth: The height of a gemstone measured from the culet to the table, noted in a percentage.

Diamond anatomy

Diamond Basics – the 4Cs

The characteristics that identify diamonds are known as the 4 Cs – cut, colour, clarity and carat. The 4 Cs is a universally recognised method of diamond grading, created by the Gemological Institute of America (GIA), to standardise the classification of diamond quality.

  • Cut: The cut of a diamond refers to how well it has been shaped and faceted. It affects the diamond’s brilliance and sparkle. The quality of the cut is graded on a scale from Excellent to Poor.
  • Colour: The colour of a diamond is graded on a scale from D (colourless) to Z (light yellow or brown). The less colour a diamond has, the higher its grade and value.
  • Clarity: Clarity measures the presence of internal and external flaws, called inclusions and blemishes, respectively. The clarity scale ranges from Flawless (no visible inclusions or blemishes under 10x magnification) to Included (visible flaws). The higher the clarity grade, the rarer and more valuable the diamond.
  • Carat Weight: Carat weight is the measurement of a diamond’s size. One carat is equal to 200 milligrams. Larger diamonds are generally more valuable, although other factors such as cut, colour, and clarity also influence a diamond’s worth.


Colour grade is important to consider when choosing a white diamond.


A clarity grade is greatly influential on a diamond's overall look.


When choosing a round diamond, it is important to choose a cut that will emphasise its beauty.


Carat refers to the weight of your diamond, not its size and sometimes bigger isn't always better.

Diamond sizes

Use our guide to compare diamond sizes.

GIA graded diamonds

Learn about the basics of diamond certification & why our centre diamond are GIA graded.

Understanding Diamond Shapes

Diamond shapes are the defining feature of a diamond’s appearance and play a profound role in its overall aesthetic. Understanding the characteristics of different diamond shapes will help you choose the perfect stone that reflects your individuality and creates a lasting impression.

One Carat Diamond

No two diamonds are exactly alike, even in ways you might not expect. These subtle differences can make knowing what size diamond to use in your ring a little tricky, but we’re here to help.

Choosing a diamond that’s the perfect size for your engagement ring is one of the most important decisions you’ll make in the ring design process. So we’ve made a simple comparison chart to help you get a better picture of what you can expect from your diamond.

carat weight

Ethical Sourcing

Ethical sourcing should be the first step in creating any piece of jewellery. We believe it’s the right thing. We know it’s the right thing. Using sustainable materials and creating ethical business partnerships is the way forward not just for Taylor & Hart but for our peers across the jewellery supply chain, and our customers should expect nothing less.

Natural vs Lab Grown Diamonds

Lab grown diamonds and naturally mined diamonds. Technically and chemically, they’re both diamonds, but they differ in their origins and how they’re produced. Known for their unmatched brilliance and iconic sentiment, let’s explore the differences between the two so you’re empowered to make a choice based on what’s most important to you.

Diamond Fluorescence

Diamond fluorescence refers to the intensity of a coloured glow (usually blue) that is visible when a diamond is exposed to UV light. In some instances, diamonds with strong fluorescence may look milky and lifeless in daylight, but in most cases, the appearance of a diamond with strong fluorescence is rarely affected. Diamonds with none or a faint fluorescence are rarer than those with a strong or very strong fluorescence.

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