What Makes Some Gemstones More Expensive Than Others?

If you've ever wondered why some gemstones cost a fortune while others are surprisingly affordable, you're not alone. 

While rarity, demand and fashion trends certainly play a role, there are several deeper reasons why certain gems command higher prices. Let’s explore the key factors that affect the value of gemstones.

Rarity

One of the biggest influences on a gemstone’s price is its rarity. Simply put, the scarcer a stone is, the more expensive it tends to be. Some gemstones, like alexandrite and grandidierite, are found in only a handful of locations worldwide, making them significantly more valuable than common stones like quartz or topaz.

Even within the same gemstone family, some varieties are much rarer than others, for example, Paraíba tourmaline is far rarer (and pricier) than standard tourmaline.

Marketing & Perceived Value

Marketing plays a huge role in gemstone pricing.

Diamonds are the most famous example, despite being relatively common, supply controls combined with clever advertising campaigns have positioned them as the ultimate symbol of love and luxury. This has resulted in them command a premium price that it could be argued they don't actually deserve.

Another fascinating example is black pearls, they were once overlooked in the pearl industry, considered a bit of a disappointment when found as they had little to no value, but one man, with a clever marketing tactic, turned them into a luxury item. Eventually making them the most expensive pearl variety.

The more a gemstone is associated with exclusivity, prestige, or an emotional connection, the higher its perceived value and, consequently, its price.

Popularity & Fashion Trends

Just like in fashion, gemstone prices fluctuate based on trends. Certain stones can experience surges in demand due to celebrity endorsements, social media, or changes in jewellery trends.

For example, when Princess Diana’s sapphire engagement ring became famous, sapphire prices saw a boost. More recently, alternative engagement ring stones like morganite and spinel have gained popularity, increasing their value.

Colour & Saturation

The intensity and purity of a gemstone’s colour can significantly impact its value. Rich, vibrant colours are usually more desirable than pale or overly dark stones. For example, the deep red of a “pigeon’s blood” ruby or the vivid blue of a “royal blue” sapphire will command much higher prices than less saturated or brownish hues.

Clarity & Inclusions

Clarity refers to the presence (or absence) of inclusions within a gemstone. In many cases, fewer inclusions mean a higher price, as clear stones are considered more visually appealing.

However, this isn’t always the case. Certain inclusions can actually add value if they enhance a gem’s appearance, such as silk-like inclusions in high-quality sapphires or rutile needles in quartz. 

Cut & Craftsmanship

A well-cut gemstone maximises brilliance (sparkle), enhances colour, and makes the stone appear more visually striking. Poor cutting can result in a dull appearance, even in a high-quality stone.

Certain shapes also impact value. Round and oval cuts tend to be more expensive due to higher material loss during cutting, while fancy shapes like trillions or cushions can sometimes be more affordable.

Size

Larger gemstones are exponentially rarer than smaller ones, which means they command higher prices per carat.

There are also "magic sizes" where prices jump significantly, such as at the 1-carat, 3-carat, and 5-carat marks. A 0.95-carat diamond may be considerably cheaper than a 1-carat stone, even if the difference in size is barely noticeable.

Origin & Provenance

Where a gemstone comes from can influence its value. Certain origins are associated with superior quality, such as Burmese rubies, Colombian emeralds, and Kashmir sapphires.

These locations have historic reputations for producing the finest specimens, and collectors often pay a premium for stones with a documented origin. Additionally, gemstones with an interesting history, such as those once owned by royalty or celebrities, can fetch astronomical prices at auction.

Durability & Wearability

A gemstone’s hardness and resistance to damage also affect its market value. Harder stones like sapphires and spinels are more desirable for everyday wear, as they resist scratching. Softer stones, like fluorite or selenite, are more prone to damage, making them less valuable for jewellery unless, like opals, they have exceptional beauty or rarity.

Treatment & Enhancement

Gemstone treatments can significantly impact price. Many gems are routinely treated to enhance their colour or clarity, such as heat-treated sapphires or oil-treated emeralds. While treated stones can still be valuable, untreated gemstones with naturally vibrant colours are much rarer and therefore command significantly higher prices. 

Supply Chain & Ethical Sourcing

A gemstone’s value can also be influenced by ethical considerations and supply chain issues. If a major mine closes, prices can rise due to reduced availability.

Additionally, ethically sourced gemstones that come with fair-trade certification or traceable origins may be priced higher due to the costs associated with responsible mining practices. 

The value of a gemstone is shaped by a combination of rarity, marketing, physical properties, and consumer demand. While rarity and quality are key drivers, fashion trends, treatments, and ethical concerns also play an increasingly important role in determining a gem’s price. Whether you're a jeweller, a collector, or simply a gemstone enthusiast, understanding these factors can help you make informed decisions when buying or selling gemstones.