Ruby, sapphire and emerald remain central to fine jewellery. Alongside them, gemstones such as spinel, tourmaline and certain garnets deserve a closer look. Understanding their appeal begins with recognising what makes an individual stone exceptional.
When we hear that coloured gemstones are attracting collector attention, it is worth asking which stones—and what kind of attention. Ruby, sapphire and emerald are familiar starting points, but they don’t tell the whole story. Exceptional spinel, Paraíba tourmaline and certain garnets also feature in the conversation about colour, quality and rarity.
The important distinction is between a gemstone category and the finest material within it. Two sapphires can differ enormously in colour, clarity, treatment and cutting. So can two spinels or tourmalines. A name introduces us to the material, but it tells us relatively little about the quality of the particular stone.
When assessing a coloured gemstone, I look at how those characteristics work together. That assessment is also a useful starting point for understanding why some stones attract particular interest, while others within the same category do not.
Looking beyond the familiar names
The term “semi-precious” can be misleading because it suggests a hierarchy before we have examined the gemstone. It places spinel, tourmaline and garnet beneath the traditional ruby, sapphire and emerald, without accounting for the extraordinary variation in quality found within each group.
An exceptional spinel or Paraíba tourmaline can be worth considerably more than an ordinary sapphire or emerald. That does not make one gemstone universally more valuable than another. It means the individual example deserves closer consideration than its traditional classification might suggest.
Education changes how we approach that decision. Once you understand the differences between gemstones, you have more possibilities to consider. You might begin with an interest in pink sapphire and discover spinel, or find that the green you are drawn to belongs to a chrome tourmaline. The assessment becomes more specific, and the choice more informed.
Why Mahenge spinel deserves attention
Mahenge spinel is a compelling example of what can be discovered beyond the most familiar names. The vivid pinks and reds we have shared recently show how striking its colour can be, particularly when careful cutting brings out the stone’s brilliance.
Fluorescence can contribute to the appearance of certain examples, adding another dimension to their colour. But the name alone cannot tell us how a particular stone will look. Each needs to be examined for its own combination of colour, clarity, cutting and overall character.
This is what interests me when selecting a gemstone: how those qualities come together in something you can actually see. A description may introduce the stone, but it cannot fully convey its response to light or the balance of its proportions.
Our Sabina Round Spinel Pendant brings natural pink Mahenge spinel into Augusta’s braided gold setting. Its faceted surface creates a lively centre within a substantial frame, showing how the gemstone and the design can give emphasis to one another.
A closer look at green
Green offers another useful way to explore the relationship between colour and gemstone identity. Emerald is often the first reference point, but chrome tourmaline and tsavorite garnet introduce different possibilities. Each deserves consideration for its own qualities.
Chrome tourmaline has featured prominently in our recent sourcing and jewellery. Its vivid green can have remarkable presence, while the cutting influences how that colour is revealed. In a saturated stone, proportions need careful consideration so that the finished gem retains both colour and life.
Recently, we shared pairs of chrome tourmalines custom cut for our Georgian earrings. Matched pairs introduce another layer of selection: the stones need to work together in colour, dimensions and appearance, as well as meet the requirements of the design.
Tsavorite offers another expression of green within the garnet family. Our Vesta Pendant has featured a 1.5-carat tsavorite, providing a specific example of a gemstone that may be less familiar to readers than emerald. Seeing these materials in finished jewellery helps make the distinctions tangible.
Cabochon describes the cut
The rhodolite garnet and chrome tourmaline cabochons recently introduced for Augusta offer a different way to experience colour. A cabochon is a smooth, domed style of cutting, rather than a gemstone species. The material might be garnet or tourmaline; “cabochon” describes the form given to it.
A faceted stone produces patterns of reflected light through its polished faces. A cabochon places greater visual emphasis on the curved surface, depth of colour and reflections across the dome. Understanding the distinction helps explain why the same gemstone material can look so different from one piece to another.
In the Sabina Oval Cabochon Pendant, rhodolite garnet sits within a generous frame of twisted gold. The Livia Cabochon Ring features a 2.3-carat chrome tourmaline above a substantial braided band. Their smooth surfaces create a particular relationship with Augusta’s textured goldwork.
These pieces belong in the discussion because they demonstrate considered choices in material, cutting and design. Their inclusion in a collection does not establish that rhodolite prices are rising, or that a cabochon is inherently more valuable than a faceted stone.
The individual stone still comes first
Looking beyond familiar gemstones does not diminish the significance of finding a beautiful sapphire. We recently shared a 6.62-carat Madagascan sapphire with deep royal-blue colour, beautiful clarity and no heat treatment. It offers a concrete example of the characteristics being discussed.
Treatment is an important part of understanding a coloured gemstone, but it needs to be considered alongside its other qualities. An untreated description does not remove the need to examine colour, cutting, clarity and condition. Nor should a recognised origin become a reason to overlook a less impressive stone.
I apply the same principle to documentation. Appropriate independent certification provides valuable information and supports an informed decision. It should be read alongside a careful assessment of the gemstone, so that the paperwork and the stone are considered together.
What does attention tell us about value?
Growing awareness, collector interest and rising prices are related subjects, but they are not interchangeable. Enquiries can indicate curiosity or demand. Sourcing experience can reveal difficulties in finding particular material. Establishing appreciation requires reliable evidence across a defined period and a meaningful comparison between stones.
That distinction matters when discussing exceptional gemstones. A significant result for one stone cannot describe every example carrying the same name. The quality, size, treatment, provenance and circumstances of a sale all need to be understood before drawing wider conclusions.
A finished jewel introduces further considerations. Its value includes design, craftsmanship and setting, as well as the gemstone itself. When choosing a piece to wear, those relationships are part of the decision: how it sits, how it feels and how the design allows the stone to be appreciated.
The most useful knowledge is therefore the knowledge that helps you look more closely. Understand the material, ask about treatment, examine the cutting and consider what makes that particular example distinctive. Whether you are discovering spinel for the first time or considering a significant sapphire, those questions provide a sound foundation for choosing with confidence.
Discover the stones in our collection
Explore our New Arrivals for selected pieces featuring gemstones discussed here, including pink Mahenge spinel, chrome tourmaline and rhodolite garnet.
View New Arrivals
Find your coloured gemstone
If a particular colour or gemstone has caught your attention, book a private appointment. We can explore suitable stones together, explain their individual qualities and discuss an existing design or a bespoke piece.
