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Diamond: April Birthstone Buying Guide

Diamonds are one of the most cherished and sought-after gemstones, renowned for their epoch-spanning beauty and being a timeless symbol of love. Buying diamonds is a significant investment, so it’s always a good idea to do some research for educational purposes, ask questions, and purchase from trusted sources. At Taylor & Hart, we have a stringent quality assurance process to ensure all our diamonds are, quite literally, a cut above the rest.

From exploring the basics of diamond quality, available shapes and cuts to delving beyond the 4 Cs and how these impact a diamond’s appearance, we’ll showcase just what makes this exceptional stone so special for April.

What is a diamond?

Diamonds have a captivating geological history spanning billions of years. The way they’re formed is utterly fascinating, if a bit scientific, so get your notepads ready. Originating deep within the Earth’s mantle, about 140 to 190 kilometres below the surface, carbon atoms undergo a transformative process under immense heat and pressure, resulting in the formation of diamond crystals.

This intricate process usually occurs within specialised areas of the mantle known as ‘diamond stability zones,’ situated beneath stable continental plates. Following their formation, diamonds remain underground until volcanic activity propels them to the surface. Magma, rising from the depths of the mantle, carries diamonds upward, ultimately erupting onto the Earth’s surface in volcanic outbursts. There, they settle within diamond-rich rock formations like kimberlite or lamproite pipes. Amazing, right?

The discovery of diamonds in India in the 4th Century BC was the start of their legacy as the cherished symbols of beauty and value that we know and love. Revered for their luminosity, durability and rarity, diamonds have transcended eras, serving as symbols of affluence, influence, and affection across civilisations.

In modern times, diamonds maintain their magnetism and are sought-after for adornment, industrial and investment purposes. They continue to captivate global imagination, reflecting both nature’s splendour and the extraordinary geological processes that shaped them.

Diamonds History and Meaning

Diamonds are believed to have been first discovered in India’s Golconda region around 2,500 years ago and were considered ‘divine treasures’ by Indian rulers. Early techniques didn’t have the same techniques of cutting and polishing as we came to know them, so they left diamonds with their natural texture. Rough diamonds were cherished as talismans before being integrated into jewellery, and rather interestingly, were initially reserved for men.

From the 10th century, Western markets gained access to diamonds through trade routes, elevating them to status symbols. Throughout the Middle Ages, diamonds were seen as prized amulets and were thought to have mystical and medicinal qualities. This is what ultimately led to the emergence of diamond rings as symbols of marriage.

In 1286, writer, Guillaume Durand highlighted the eternal qualities of diamonds, associating them with love and marriage. This tradition persisted, with diamond rings symbolising engagement and unions for subsequent centuries. Innovations in diamond cutting techniques, most notably in Italy and Belgium, revolutionised craftsmanship, introducing intricate faceted and fancy cuts that enhanced the brilliance of these gems.

There, they entered a more modern machine-cutting phase of diamond jewellery. From the early 1900s, machinery cut gemstones started entering the market and so began this revolution where precious gemstones and diamonds became the norm for engagement rings for those who could afford them.

Diamond – April’s Birthstone

April’s association with the diamond likely stems from its purity and strength, mirroring the themes of renewal and rebirth during this month.

Over time, the diamond’s endless appeal solidified its position as April’s birthstone. Cultural influences and historical events further supported this association, integrating the diamond into various aspects of society. Today, it remains a cherished symbol for April birthdays, embodying clarity, strength and everlasting beauty. Its prominence in art, literature and fashion ensures it continues to shine as an emblem of April and those born during this transformative month.

Diamond Quality: The 4 Cs

Diamond quality is evaluated using a set of criteria commonly referred to as the 4 Cs which stand for: carat weight, cut, colour and clarity. These factors provide a comprehensive assessment of a diamond’s overall quality and value.

Diamond Carat Weight

Carat weight refers to the mass of the diamond and is often the first characteristic people consider when evaluating its quality. For reference, one carat is equivalent to 200 milligrams. Larger diamonds are generally rarer and more valuable, so carat the weight will significantly impact a diamond’s price. However, it’s important to note that carat weight alone does not determine a diamond’s quality and other factors also play crucial roles.

How does diamond carat weight impact oval engagement ring price?

Because larger diamonds are rarer, the heavier the diamond, the higher the price. For example, a 1ct oval diamond would be valued higher than two 0.50ct oval diamonds of the same quality. In general, doubling the size of your diamond can cost three to four times more.

Highly sought-after oval diamond sizes can also carry a price premium. If you’re after a larger stone, we recommend buying just shy of your desired carat weight, which can help with savings.

You can often save about 10% by choosing a diamond that’s around 0.10cts lower than the popular sizes. They’ll appear almost identical in size but won’t carry the same price tag.

Nikolay Piriankov, CEO at Taylor & Hart

The cut of a diamond refers to its proportions, symmetry and polish, rather than its shape. A good cut of a diamond can maximise its brilliance, fire and sparkle by letting the light to enter and reflect in the most pleasing way. The quality of a diamond’s cut directly affects its visual appeal. Diamonds are graded on a scale from Excellent to Poor based on their cut quality.

Diamond Colour

Diamond colour, quite simply, refers to the presence or absence of colour in a diamond. The Gemological Institute of America (GIA) grades diamond colour on a scale from D (colourless) to Z (light yellow or brown). Colourless diamonds (graded D to F) are the rarest and most highly valued because they allow the optimal amount of light to pass through, resulting in maximum brilliance. As the colour grade moves down the scale, the presence of colour becomes more pronounced, diminishing the diamond’s aesthetic appeal and value.

Diamond clarity assesses the presence of internal and external flaws, known as inclusions and blemishes, within a diamond. The GIA grades diamond clarity on a scale ranging from Flawless (no inclusions or blemishes visible under 10x magnification) to Included (inclusions visible to the naked eye). Diamonds with higher clarity grades are rarer and more valuable because they have fewer imperfections that can detract from their brilliance and overall prettiness.

That’s the 4Cs covered, but there are other factors to consider when evaluating diamond quality. Fluorescence, for example, refers to a diamond’s reaction to ultraviolet light, and there’s certification, which verifies a diamond’s characteristics and ensures its authenticity.

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 and the most visible-to-the-eye feature of a diamond’s appearance and play a pretty big 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.

Diamond Anatomy

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

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 probably 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.

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. We strongly believe 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. It makes much more sense with visual aides, trust us.

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