Color Changing Gemstones: What Are They and Should You Consider Buying One?

When selecting or custom designing a new piece of jewelry, it can be daunting to decide on a gemstone for the focal point, especially if you are drawn to multiple different colors. You may be asking yourself if you should pick a classic blue sapphire, a bright red ruby, or a deep green emerald. Or maybe the options are just far too vast that you decide on a diamond just so you don’t have to choose a color.

For indecisive people, color changing gemstones offer a solution to this problem. These unique stones provide the consumer the ability to select not one color, but most often two because these gemstones change colors depending upon the lighting, making them the perfect choice for a unique piece of jewelry to add to your collection.

Color changing gemstones are not only visually stunning, they also add versatility to your jewelry box. Plus, they’re sure to be a conversation starter, as not many people are familiar with color changing gemstones. People are often fascinated after seeing a stone change color right before their eyes.

Gemstones as a whole have been a source of interest for humans since they were discovered, but very few of them have the ability to change their color. Let’s dive into the world of color changing gemstones so we can not only learn about why their colors change, but also learn about the different types. 

What Causes Gemstones to Change Color? 

Color changing gemstones react to different light sources in specific ways that cause their colors to change. This is called pleochroism (also sometimes referred to as the Alexandrite effect). It occurs when certain elements within the gemstone react to specific light wavelengths. Different types of light such as daylight, incandescent, or LED can affect these gemstones in different ways, causing the color change. 

There are certain elements that tend to react to these different light sources. If there are traces of chromium, vanadium, or iron in the gemstone, they can affect how the light passes through the stone and this creates the color change that we see. For example, the red-to-green color change in Alexandrite is caused by chromium, resulting in a dramatic shift. In contrast, vanadium—responsible for the color change in both sapphires and garnets—produces a more subtle effect. The gemstone's crystal structure also plays a role, as it influences how light passes through the stone, further affecting the color change.

This explains why two alexandrites may change to slightly different shades of green or red, and also why the color change can be more or less visible in similar stones.  

If you step outside into natural daylight, which has a balanced spectrum, your stone will most likely show its primary color, i.e. the color it will "be" most of the time. But if you’re in an office with LED lights or a nightclub with black lights, your stone will shift to a different color–or switch back and forth between the two.

The Most Popular Color-Changing Gemstones

1. Alexandrite: Definitely the most commonly known color changing gemstone, Alexandrite has quite possibly the most drastic color change as well. The chromium present in Alexandrite causes the stone to change from an emerald green color in natural daylight to a ruby red or purple color when in incandescent lighting. Alexandrite was originally discovered in 1830 in Russia’s Ural Mountains and was named after the future Russian Tsar Alexander II. Today it is mined in Brazil, Sri Lanka, India, Madagascar, and Zimbabwe.

2. Garnet: While garnets are mostly known for their deep red color (Almandine and Pyrope), they are also available in a variety of other color options such as Spessartine (orange), Grossular (yellow or brown), Tsavorite and Demantoid (green), and Rhodolite (pink or purple). The rare color changing garnet typically changes from greenish hues in daylight to reddish or purplish tones in artificial lighting.

Although the color change is similar to that of Alexandrite, the element causing the change is different; garnets change because of the presence of vanadium and iron. The earliest existence of garnets were in areas such as Sri Lanka and India, while today they are mined in various parts of the world including their original sources–in addition to Brazil, Kenya, and even the United States. 

3. Sapphire: While sapphires are typically known for their rich blue color, they are also available in pink, yellow, green, purple, orange, and even colorless (white sapphires). One of the most rare types of sapphires is the Padparadscha sapphire, which has a gorgeous pink-orange color. Color changing sapphires are even more rare and usually change from blue to violet in different types of lighting due to the vanadium that is present in the stones. Originally discovered in Sri Lanka, sapphires are mined in a variety of places throughout the world including Australia, Madagascar, and Montana. 

4. Spinel: Spinel is not quite as popular as the previously mentioned gemstones, but it is available in a surprisingly wide array of colors such as red (often confused for rubies), pink, orange, purple, blue, and black. Many famous stones that were considered rubies were later found to be spinels, such as the Black Prince’s Ruby in the British Imperial State Crown. Color changing spinels can change from blue to violet, or gray-blue to purple-red. Originally discovered in Sri Lanka, they are now mined in many places including Myanmar and Tanzania.

5. Zultanite: Not commonly known, zultanite is mostly found in Turkey, where it was originally discovered in the Anatolian Mountains. This gemstone changes from a kiwi green color in natural daylight to a pink-champagne color in incandescent light.

How to Care for Color-Changing Gemstones

Like all colored gemstones, color-changing gems require proper care to maintain their beauty and prevent damage. Before cleaning, be sure to consult a jeweler or do your research to ensure you’re using the right methods.

Avoid exposing these gems to harsh chemicals, and store them away from dust and other stones to prevent scratches or damage. It's also important to limit their exposure to unnecessary UV light, as it can affect their color-changing properties or cause the color to fade over time.

Since color changing gemstones are so rare, they can demand a fairly high price tag, however if you can afford them they are certainly a worthwhile investment. As with all jewelry purchases, always look for gems that come with a certification from a reputable gem grading laboratory and be sure to purchase them from a trusted jeweler or gem dealer. 

Color-changing gemstones are both fascinating and stunning, making them a unique and elegant choice for any jewelry piece. Whether you appreciate them as interesting jewelry pieces or you’re a gemstone collector, they offer a versatility that cannot be found with other types of gems. From the well-known Alexandrite—with its striking green-to-red shifts—to the more subtle Zultanite, which moves from kiwi green to champagne pink, these gems make a beautiful addition to any collection. Just be sure you understand their unique properties, how to best view their color changes, and how to care for them properly.