Which Sapphire Colours are the Rarest?
While coloured gems, especially sapphires, were once one of the most popular jewels used for engagement and wedding jewellery (just ask the Royal Family), they’ve definitely taken a back seat since the A Diamond is Forever campaign hit in 1948. Now, various factors, including: an interest in injecting more personality and individuality into wedding jewellery, the desire for rarity and true value, and the popularity of lab-grown diamonds potentially making natural diamonds less interesting to consumers, are all contributing to coloured gems once again gaining favour in the realm of engagement rings.
Due to their wide variety of colours, excellent toughness and hardness, and regal reputation, sapphires are one of the leading choices when it comes to choosing a coloured gemstone. However, if you’ve been in the market for a blue or “fancy-coloured” sapphire, you may have been a bit bewildered at the wide range of price points. To help guide you, we’ve generally rated them below from most rare to least, as well as listed some additional considerations while in the market for each.
Red
Never heard of a red sapphire before? There’s good reason, since they’re actually rubies. Both sapphires and rubies are part of the corundum mineral group, but the colour red in gems is so rare and hard to come by that rubies earned their own name (and rich historical provenance to match.) In their best qualities, rubies are the rarest gem on Earth and command a higher price per carat than any other gemstone, including diamonds.
The 55.22 carat Estrela de Fura ruby also just set the world record price of $34.8 million USD with Sotheby’s in June 2023 as the most expensive gem ever sold at auction, period. The best quality rubies (and sapphires) tend to be those formed in metamorphic environments, which means they’re low in iron. Iron can give both gems a dark tone and an appearance of low saturation (i.e. a brownish or greyish haze). A metamorphic environment, including those found in Myanmar, Sri Lanka and Mozambique, can also give a ruby fluorescence, which means it will glow like Rudolph’s nose in UV light. It’s a bit of a niche quality that can definitely add even more value to already excellent quality stone. Otherwise, it might just serve as more of a conversation piece. Overall, the most valuable rubies will have a medium to medium-dark red hue with a bright, sparkling transparency and a richly saturated colour. The last factor to consider when examining various price points is the condition of heat treatment. It’s estimated that nearly 90% of coloured gems are heated to improve their colour—so understandably the lack of such treatment is considered a major rarity and can increase the value of any particular gem (and most especially an already very rare ruby) exponentially. Keep in mind, heat treatment is becoming harder to identify and realistically, will likely have little to no effect on your overall enjoyment of the jewel.
Pink
Of course, rubies with a less saturated hue will naturally be labelled as pink sapphires. Still considered a rarity for their display of chromium—the highly scarce element responsible for the red hue in corundum—the highest quality pink sapphires will be a “hot pink” versus a lighter tone of watercolour pink. With all gems, your preferences are obviously what matter the most, however know that with any hue, less saturated stones will command lower prices.
Highly-coveted pink hues also include padparadscha sapphires, which should have an eye-pleasing and unique combination of orange and pink hues, like the lotus flowers they’re named after.
Blue
Since blue is considered the world’s favourite colour and it practically represents life on earth thanks to the water, sky and everyone’s fave blue jeans, blue sapphires are the most popular gem after diamonds. It doesn’t hurt that one of the most famous engagement rings of all time also features one. Due to their popularity, blue sapphires are probably one of the more difficult colours to shop for since there is such an overwhelming variety and wide range of qualities. Similar to rubies, the highest qualities generally have a medium to medium dark tone with a vividly saturated colour and a crystal-like transparency without any brownish or greyish tint. Again, metamorphic environments are the most well-known for producing these types of stones.
Sri Lankan sapphires are particularly famous (they are still most often referred to as “Ceylon” sapphires) as they are metamorphic, but can also have a very pleasing purplish tint which is sometimes referred to as cornflower blue. Blue sapphires with a greenish tint, which became somewhat fashionable in recent years, also indicate a high presence of iron, which makes the gem among the less valuable, including blackish-blue and highly opaque stones. Blue sapphires are probably the most heated-treated of all of the colours due to their popularity in more mainstream and mass-market jewellery. However, if you’re in the market for a high-quality gem with long-term investment potentially, a blue sapphire is the probably the variety in which searching out an unheated stone is the most pivotal.
YELLOW
Like many coloured gems, yellow sapphires can vary in value depending on where you are in the world, and their specific popularity in that region.
While yellow sapphires have been very sought-after in Asian countries including India, Sri Lanka and Thailand for decades, they’ve just recently gained more traction in North America, thanks to the popularity of the colour yellow in general. Golden, orangish-yellow sapphires are the most valued while, again, those with lighter tones, less saturation, and a greenish tint being considered much less desirable. Since yellow is already a lighter hue, avoid windowing on stones as much as possible. This refers to areas in the gem (usually in the centre) seen through the top table facet which appear completely see-through and void of light return, as if you could easily read text through it. Windows are a common side effect of coloured gems which are cut a little too shallow in order to increase their face-up dimensions, thus making it look larger than it is.
While purple sapphires are one of the most uncommon, they can be incredibly unique and appealing. Most violet stones are either purplish-blue or purplish-pink, but a true purple or even lavender sapphire, while not necessarily in-demand (and therefore generally lower in price) is a treasure for any purple lover for its unique nature alone.
Purple
Green
With plenty of other green gems on the market with more rarity, light refraction and history, including emeralds, demantoid and tsavorite garnets, green sapphires are generally not high on the list of sought-after jewels. Since green is usually a hue that is avoided in other sapphire varieties, a true green sapphire should be special in its presence, saturated colour and crystal transparency.