When you’re looking for a captivating jewelry piece or striking gemstones to add to your collection, colour-change gemstones are an excellent addition. The shifting hues make the different colors of the stone visually intriguing, giving the gems that little something extra in different light settings.
Overall, color-change gemstones are relatively rare in a grander sense. When it comes to individual gemstone types, some are exceedingly rare, while others are more accessible. How dramatic the color change is in these gems also varies. Some transition between two complementary colors, while others shift to analogous hues.
Regardless of the rarity or degree of color shift, these stones have a unique beauty you typically don’t see in other gems. Whether you are a mineral collector or you’d like to add one of these phenomenal colour-changing gemstones to your jewelry collection, here is a list of gemstones with colour-change phenomena you might want to explore.
8 Colour Changing Gemstone Varieties
1. Alexandrite
If you’re discussing any colour-changing gemstones, you have to mention alexandrite. It’s the most expensive colour-shifting gemstone among naturally occurring specimens, and fine-quality stones can exceed diamond prices per carat, though lab-created alexandrite is often surprisingly affordable and doesn't come with the premium price attached to its natural counterpart. First discovered in Russia, alexandrite is also one of the birthstones for June, alongside pearl, making it a meaningful option for anyone born in that month.
In most cases, the base alexandrite colour is described as a mossy green with a slight bluish cast in natural daylight, but it shows different hues depending on the light source because trace elements such as chromium and vanadium create selective absorption within the crystal. However, under different lighting conditions, alexandrite can shift from green or teal in daylight to red under incandescent light, often with a slight purplish or raspberry tint. This colour change effect is essentially an optical illusion caused by light absorption: daylight carries a balanced spectrum, while incandescent bulbs lean heavily red. As a result, many describe alexandrite as emerald by day, ruby by night.
Because green and red are complementary colours, the alexandrite effect creates a dramatic colour change often considered the most dramatic in gems. High-quality natural alexandrite is judged primarily by the percentage of change and the intensity of the shift, which determines value more than clarity. The alexandrite colour-change phenomenon is especially noticeable when the daylight-to-incandescent shift is strong. While you can see a similar colour change in some lab-created alexandrite gems, others won’t have the same colour characteristics. Instead, the base shade might appear bluer, and the secondary hue heads into purple territory. As a result, most people looking for the classic day-ruby-by-night look generally prefer genuine alexandrite, especially when the stone changes from green in daylight to red at night.
2. Colour Change Garnet
Garnet is another gem that can change colour in different lighting, and colour-change garnet is one example of how garnets and other minerals show this effect. A colour-change garnet may shift from brownish green in daylight to pink under artificial light, while some stones can appear brown and transition to reddish purple or pink or begin as a bluish-green stone and end up purple, with colours depending on the light source. Others are more subtle, going from deeper shades of earthy red to lighter oranges, truer or purplish reds, or raspberry pinks.
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Since garnets come in a range of hues, the colour-change properties can also run the gamut when it comes to colour change. Most colour-change garnets will exhibit three different shades: one in daylight, one in incandescent light, and one in candlelight. However, some may have only two colour changes.
Usually, if you’re looking for a colour-change garnet, you’ll need to focus on pyrope or spessartite, as those varieties more commonly have the characteristic. Colour-change garnets are generally more affordable than alexandrite, making them a practical option for budget-conscious buyers. However, other varieties may also exhibit colour-shifting properties, and notable sources around the world include Tanzania. Strong colour-changing specimens are especially valuable to collectors when the shift is obvious.
3. Andesine
Andesine is a feldspar mineral with colour-changing potential. Not all of the stones will change to different colours. Instead, they typically have relatively stable colourations, looking red, green, yellow, or pale yellow.
With colour-changing andesine, you usually see green and red in the stone, depending on the lighting and angle. As a result, in faceted andesine, some segments may remain green while others show earthy red hues.
Sometimes, the colour shifts you see can also move between green and violet or purple. Again, the different hues are easiest to observe when the andesine is faceted.
Technically, colour-changing andesine is a slightly controversial stone, as many are treated to strengthen the red hues. While most gems are natural, treated gemstones aren’t in their original state, which is why some people have reservations about the stone. However, if you’re looking for phenomenal gems, andesine is worth considering.
4. Colour Change Sapphires
When you think about a colour-changing gemstone, a colour-change sapphire doesn’t usually come to mind. This is mainly because colour-changing sapphires are rare and expensive, so they aren’t widely available on the market.
With a colour-change sapphire, the gemstone appears blue in daylight and shifts toward purple under different lighting conditions. The transition happens under varying light conditions, though how dramatic it looks varies by stone. The overall appearance and intensity of the shift can range from barely noticeable in natural light, with only a slight purple tint, to dramatic enough to make a sapphire look like a bright purple amethyst under the proper lighting. Like garnet and spinel, sapphire is one of the minerals that can change colour under different lighting.
5. Diaspore
The colour change diaspore exhibits is incredibly striking. Under bright light, the colour is typically lime green or kiwi green, not unlike what you may see with peridot; under low light, it shifts from green to champagne and, in very low light, can even show pink, making these prized colour-changing specimens. In incandescent light, the hue usually falls in champagne territory, though it can potentially be an earthy light yellow.
Zultanite is a variety mined in Turkey that changes colour. While it’s marketed under another name, the zultanite gemstone is technically diaspore. That means the zultanite colour change is the same as what’s described above.
Csarite is another name for a colour-change variety of diaspore. This phenomenon is one reason collectors prize the gem. However, those listed under the zultanite moniker usually have the most dramatic colour change, so buyers often seek that trade name when achieving the strongest shift.
6. Spinel
While spinel isn’t known for an incredibly strong colour change, some examples of colour-change spinel do shift hues slightly. This is most common with deep blue spinel. In those cases, the shade of blue may simply lean toward purple under indoor light.
One benefit of colour-change spinel is that while it’s more expensive than some varieties, it isn’t necessarily the highest-priced version of the gemstone. Instead, it sits near the middle in cost, so it can be a more budget-friendly option than alexandrite while still offering this effect. On the Mohs scale, spinel is harder than fluorite, which helps explain its practicality for jewelry.
7. Colour Change Fluorite
Fluorite comes in a wide range of colours, so many would assume that any colour-shifting properties you see are natural. While some pieces of fluorite will have colour-changing capabilities on their own, that’s relatively rare rather than commonly found. Instead, colour-change fluorite gems are often subject to treatments to augment that trait, so buyers should check for any enhancements and make sure they’re clearly disclosed. By irradiating fluorite, a blue gemstone can appear blue in daylight and purple under incandescent light.
In some cases, colour-changing fluorite may have different shades across the stone. Depending on how it’s faceted, that can affect its appearance and create the look of a colour change, as the other colour isn’t visible from all angles.
One essential thing to note about fluorite is that it’s relatively soft, ranking low on the Mohs scale. Clean colour-changing gemstones gently with warm soapy water, avoid ultrasonic cleaners and harsh chemicals, and store pieces separately to prevent scratches. Fluorite isn’t ideal for jewelry without the right setting since it’s somewhat easy to damage. As a result, it’s best to limit fluorite to low-contact jewelry pieces, such as pendants and earrings, and avoid it for rings and bracelets.
8. Topaz
In some cases, topaz exhibits a strong fluorescence that creates colour-changing properties. However, this is usually most visible under the blue wavelengths of UV light and is typically quite subtle. For example, a blue or colourless topaz may exhibit a slightly yellowish or greenish tint under long-wavelength UV.
Some topaz is also irradiated to alter the base hue or increase the odds of a colour shift under specific lighting conditions. You’ll also see topaz and other gemstones being treated with coatings, with treatments and modern methods allowing more stones to display altered or enhanced colour effects.
For example, mystic topaz is a coated stone. After the treatment, the gem has a rainbow-like colour effect. However, this differs from the natural colour change phenomenon found in rarer gems, which are especially prized because nature, not a surface coating, causes the effect.
