A Gem That Changes With the Light
There are few gemstones in the world that rival tanzanite’s ability to transform with light. Discovered only once — in the foothills of Mount Kilimanjaro — tanzanite is celebrated not only for its rarity but also for its mesmerising play of colour. Depending on the lighting, it may appear violet, blue, or even a hint of burgundy, shifting tone as gracefully as the daylight across Cape Town’s skyline.
This remarkable characteristic is more than an aesthetic wonder; it’s a natural phenomenon that has fascinated gemmologists and jewellery collectors alike. At Prins & Prins Diamonds, our experts understand how light interacts with tanzanite’s inner structure, and how this unique optical effect — known as pleochroism — transforms each gem into a living canvas of colour and brilliance.
The Science of Pleochroism
To understand tanzanite’s shifting hues, one must first look within the gem itself. Tanzanite, a variety of the mineral zoisite, is pleochroic — meaning it can display more than one colour when viewed from different directions. This effect occurs because of how tanzanite’s crystal structure absorbs and reflects light differently along each axis.
In its natural state, a tanzanite crystal shows three distinct hues: blue, violet, and reddish-brown. When heat-treated — a standard process that enhances clarity and colour — the brownish tone disappears, leaving only the vibrant spectrum of violet-blue for which the gem is prized.
This optical property means that no two tanzanites ever look exactly alike. The precise balance of violet and blue depends on the orientation of the crystal, the way it’s cut, and most importantly, the light that illuminates it.
How Lighting Reveals Tanzanite’s True Colours
Tanzanite is a gemstone of light. Its beauty changes dramatically depending on the type, direction, and warmth of illumination.
- Natural Daylight:
Under natural daylight — especially in Cape Town’s crisp morning sun — tanzanite reveals its most balanced hues. The gem’s deep royal blue emerges strongly, tinged with subtle violet undertones. This is considered its truest, most natural expression. - Incandescent Light (Warm Indoor Lighting):
In softer, golden light — such as candlelight or traditional bulbs — tanzanite’s violet tones become dominant. The gem takes on a warmer, romantic hue, glowing almost lilac in ambience. This shift gives tanzanite a uniquely emotive quality, as if its colour adapts to mood and moment. - LED and Fluorescent Light:
Under cooler modern lighting, such as LEDs or fluorescents, tanzanite may appear slightly more blue or even silvery, with reduced depth in the violet spectrum. This clarity, however, enhances the stone’s brilliance, especially when set in white gold or platinum.
The same gem can look entirely different when viewed under these three lighting conditions — an effect that explains why collectors often remark that tanzanite has a “personality.” It responds to its surroundings, reflecting both light and emotion.
At Prins & Prins Diamonds, this phenomenon is carefully considered when designing each piece of jewellery. Our master goldsmiths and gemmologists understand that tanzanite’s relationship with light is not accidental — it is the very essence of its charm.
Cut, Setting, and Metal Choice – The Art Behind the Glow
While lighting determines how we see tanzanite, the way the gem is cut determines how it interacts with that light.
Because of its pleochroism, expert cutters orient the crystal precisely to achieve the desired balance between blue and violet. A slight change in cutting angle can shift the gem’s dominant hue dramatically. This is why true tanzanite expertise requires more than technical skill — it requires an artistic eye.
The setting and metal choice also influence perception.
- White metals such as platinum or white gold amplify the gem’s cooler, royal blue tones, enhancing brilliance and contrast.
- Yellow or rose gold, on the other hand, gently warm the gem’s appearance, allowing its violet undertones to emerge more vividly.
At Huguenot House, the Prins & Prins atelier ensures every tanzanite is set in a way that complements its natural optical character. Whether crafted as a pendant, ring, or pair of earrings, the goal is always the same — to allow light to move freely, illuminating the gem’s depth and duality.
This meticulous balance of science and artistry is what transforms tanzanite from a mineral into a masterpiece.
Tanzanite and Emotion – The Mood of Colour
Tanzanite’s beauty is not merely visual; it is emotional. Its shifting hues evoke the transitions of life itself — calm blue for serenity, violet for passion, and fleeting flashes of pink or red for vitality.
For many, this dynamic spectrum symbolises transformation and rebirth. It’s why tanzanite has often been chosen to mark new beginnings — a first anniversary, a child’s birth, or a milestone achievement. Unlike static gemstones, tanzanite feels alive, capturing the poetry of change in every glint of light.
The psychological effect of its colour is equally powerful. Blue is associated with trust and wisdom, while violet represents imagination and spiritual insight. Together, they form a harmony of reason and emotion — much like a balanced partnership or enduring love.
Cape Town’s Light – A Unique Setting for Tanzanite
Few cities in the world offer light quite like Cape Town. From the golden morning glow over Table Mountain to the soft afternoon shimmer across the Atlantic, this unique quality of light has long inspired artists — and enhances the brilliance of gems displayed within it.
Inside Huguenot House, the home of Prins & Prins Diamonds, this natural illumination filters through sash windows onto showcases of tanzanite. Here, the gem’s violet-blue fire seems to echo the colours of the Cape itself — the deep ocean blues, the floral purples of fynbos, and the warm reflections of late sunlight on heritage wood.
This harmony between nature, architecture, and artistry is what defines the Prins & Prins experience. Each tanzanite is presented not under artificial glare, but in authentic Cape Town light — the very environment that reveals its truest character.
The Art and Science of Colour
Every tanzanite tells a story — not just of where it was mined, but of how it interacts with light, design, and emotion. It is both science and poetry, crystal and colour, history and craft.
At Prins & Prins Diamonds, we celebrate that duality. Each gem is hand-selected and set by artisans who understand that lighting, craftsmanship, and legacy are inseparable. Whether viewed in the morning sun or under evening candlelight, a Prins & Prins tanzanite reveals a beauty that is as changeable — and as enduring — as love itself.
Explore the rare beauty of African colour and craftsmanship with our collection of Tanzanite Jewellery, designed to capture light in all its brilliance.
