Everything You Need to Know About Sapphire – Colours, Quality & Buying Guide

on Feb 12 2025

What Is Sapphire?

Sapphire is a precious gemstone known for its stunning colours, durability, and versatility. It belongs to the corundum mineral family and is second only to diamonds in hardness. While blue is the most well-known colour, sapphires come in many shades, including pink, yellow, green, and even colourless.

Many people think sapphire only refers to blue gemstones, but this is not entirely correct. In the jewellery world, sapphire includes all corundum gemstones except red ones, which are called rubies. Corundum is made of pure aluminium oxide (Al₂O₃), and when no trace elements are present, it is colourless. Different elements create different colours:

Blue Sapphire: Contains iron (Fe) and titanium (Ti).
Pink Sapphire: Has traces of chromium (Cr).
Yellow & Green Sapphire: Gets its colour from iron (Fe).
Padparadscha Sapphire: A mix of pink and orange hues, highly valued.

Sapphires can be found in a range of colours, including white, yellow, green, and purple. If a sapphire is not specifically identified by its colour, it usually refers to the blue variety. It is also important to note that while many gemstones like tanzanite, blue topaz, and aquamarine are blue, they are not sapphires, as they belong to different mineral families.

Sapphires are very hard, scoring 9 on the Mohs scale, making them one of the toughest natural gemstones, just below diamonds. Sapphire is a timeless choice for those seeking elegance and durability. Because of their strength and beautiful colours, they are popular for jewellery, engagement rings, and royal collections.

How Do Sapphires Form?

Sapphires form under high heat and pressure deep in the Earth. Over time, they come to the surface through volcanic activity. The best sapphires come from Sri Lanka, Myanmar (Burma), Kashmir, Madagascar, and Australia.

Sapphire vs. Other Blue Gemstones

Many gemstones are blue, so it is easy to confuse them with sapphire. Here’s how they compare:

Gemstone	Hardness (Mohs)	Colour Range	What Makes It Different?
Sapphire	9	Deep to light blue, also other colours	Very strong, deep colour
Tanzanite	6.5 – 7	Purplish-blue	Softer, needs careful handling
Blue Topaz	8	Sky blue to deep blue	Often heat-treated, lower cost than sapphire
Aquamarine	7.5 – 8	Light blue to greenish blue	Lighter colour, not as deep as sapphire
Spinel	7.5 – 8	Bright blue to dark blue	Often mistaken for sapphire, more affordable

Sapphires are stronger and more scratch-resistant than most other blue gemstones, making them last longer.

How to Check Sapphire Quality (The 4Cs)

When buying a sapphire, experts look at four things: Colour, Clarity, Cut, and Carat Weight.

1. Colour – The Most Important Factor

The best sapphires have a rich, even colour. The key points are:

Hue: The main colour and any extra shades (e.g., purplish-blue, greenish-blue).
Saturation: How strong the colour is.
Tone: Whether the colour is light or dark.

💎 Best Colour: Royal Blue and Cornflower Blue are the most valued shades.

2. Clarity – How Clear the Stone Is

Sapphires often have tiny marks inside them. Unlike diamonds, they do not need to be flawless. However, fewer marks make the stone more valuable.

Common Inclusions: Fine needle-like lines, tiny spots, or cloud-like shapes.
Best Clarity: Stones that look clear to the eye are worth more.

3. Cut – How the Stone Is Shaped

A good cut makes the sapphire shine. Popular cuts include:

Oval & Cushion Cuts: Keep more of the stone’s weight and give great sparkle.
Round & Princess Cuts: Have a balanced look and shine.
Emerald & Asscher Cuts: Step-cut shapes that have a classic feel.

4. Carat Weight – How Big the Stone Is

Sapphires come in many sizes, but a bigger stone is not always better. A well-cut 2-carat sapphire with rich colour can be worth more than a 5-carat sapphire with a dull tone.

💡 Tip: The most popular size for engagement rings is between 1 and 3 carats.

Summary

Sapphire is a stunning gemstone with many colours, strong durability, and a long history. It is used in fine jewellery and has remained popular for centuries. The most important thing when choosing a sapphire is its colour, followed by clarity, cut, and size.

Sapphires are a perfect choice for engagement rings, necklaces, and heirloom jewellery. Whether you prefer a deep blue sapphire, a rare padparadscha, or another colour, there is a sapphire for every style.