Sapphire and Ruby: Iconic Gemstones
Are there any more iconic gemstones than sapphire and ruby? Excepting perhaps diamond and emerald, they are clearly among the most well known and prized gemstones. Rubies and sapphires are actually both varieties of the mineral corundum. This mineral is composed of aluminum oxide and what makes a gem either a sapphire or a ruby is slight variations in their chemical composition.
Here we’re going to explore where sapphire and ruby were first discovered and their history, their formation, what makes them different and some famous examples. But before we do that, here is a silly, little poem that we wrote to describe the difference between sapphire and ruby: Rubies are red, sapphires are blue. Except that’s not strictly true. Barring red, sapphires come in every hue!
Discovery and Historical Significance of Sapphire and Ruby
Corundum crystals were first discovered and prized in ancient India and Myanmar (formerly Burma). These regions have a long-standing reputation for producing some of the finest rubies and sapphires in the world and that continues to this day. Ancient civilizations valued these gems not only for their beauty but also for their perceived mystical properties. Rubies, in particular, were associated with power and protection, while sapphires symbolized wisdom and purity.
The highest quality sapphire and ruby came from South East Asia. For ruby the highest quality came from Myanmar (formerly Burma) and for sapphire the highest quality came from Kashmir. The mines where those standard setting gems came from have long since run out. But the material coming from this area is still of very high quality.
Another point of historical significance for sapphire and ruby is their inclusion on the traditional birthstone list. Rubies are the birthstone for the month of July and sapphires are the birthstone for the month of September.
Composition and Hardness of Sapphire and Ruby
Rubies and sapphires are both composed primarily of aluminum oxide (Al₂O₃). Their remarkable hardness, rated 9 on the Mohs scale, is second only to diamonds. This hardness makes them a great choice for jewellery you wear everyday such as an engagement ring. But sapphire and ruby are also great choices for any type of fine jewellery.
Defining Characteristics: Ruby vs. Sapphire
What Makes a Ruby?
A ruby is defined by its vibrant red color, which results from trace amounts of chromium. The intensity and hue of red can vary, but for a corundum crystal to be classified as a ruby, it must exhibit a dominant red color. When the red hue is not strong enough, the stone is classified as a pink sapphire instead. The boundary between pink sapphire and ruby can be subjective and varies in different markets.
The most prized shade of ruby is known as pigeon blood red (we know, gross). A true red ruby is one of the most expensive gemstones on the market, even more expensive than diamond. This is because a true red hue is very rare.
What Makes a Sapphire?
Any colour, except red, of the mineral corundum is classified as a sapphire. From the traditional blue to white, yellow, orange, pink, green and purple. If the material is more pinkish than red it will be classified as a sapphire. If the material is more red with a bit of pink it will be classified as a ruby.
The different colours of sapphire result from trace elements other than chromium present in the crystal structure. For instance, iron and titanium create blue sapphires, while iron alone can produce yellow and green hues.
Padparadscha Sapphire
One of the rarest and most coveted varieties of sapphire is the padparadscha, characterized by a pinkish-orange hue. The name “padparadscha” is derived from the Sinhalese word for lotus blossom, reflecting the gem’s distinctive color. These stones are predominantly found in Sri Lanka, with their unique colouration attributed to a mix of chromium and iron.
Famous Sapphires and Rubies
Legendary Gems
Throughout history, several rubies and sapphires have gained fame for their size, beauty, and historical significance. Among the most renowned rubies is the “Sunrise Ruby,” a 25.59-carat gem of exceptional colour and clarity, which set a world record at auction. The “Sunrise Ruby” is a perfect example of the prized ‘pigeon blood red’ colour.
For sapphires, the “Star of India” stands out. This massive, 563.35-carat star sapphire, housed in the American Museum of Natural History, is famed for its asterism. An asterism is a star-like phenomenon created by needle-like inclusions within the stone.
Another iconic sapphire is the “Logan Sapphire,” a 423-carat blue sapphire known for its deep, rich color. This gem, also on display at the Smithsonian Institution, is one of the largest faceted sapphires in the world.
Perhaps the most well known sapphire is the one that is set within Princess Diana’s and now Princess Catherine’s engagement ring. Although not exceptional in size, it is still without doubt a legendary stone.
Let’s sum up. What have we learned about sapphire and ruby?
- they are actually just different colours of the same mineral
- while ruby must always be red, sapphires are available in many different colours
- they have been prized since ancient times
- exceptional and rare examples are very valuable
- with a hardness second only to diamond they are very suitable for everyday wear
If you have any other questions or if you would like to create your own piece of sapphire or ruby jewellery, we’d love to help! Please reach out to us or complete our quote request form.
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