Rock Discoveries

The Phenomenon of Gemstones Changing Colors in Different Light Settings

Gemstones That Change

Color in Different Light Settings

Have you ever come across a gemstone that appears to change its color under different lighting conditions? At first glance, a gemstone may look green, but when placed under incandescent light, it appears blue.

This remarkable phenomenon is referred to as color change, and only a few gemstones have this property. In this article, we will explore some of the gemstones that exhibit color-change properties and what makes them unique.


Alexandrite is a rare variety of chrysoberyl that exhibits color-changing properties. Discovered in the Ural mountains in Russia in the early 19th century, alexandrite has been prized for its remarkable shift in color from green to red.

In natural light, it has a green hue, but under incandescent light, it appears reddish-purple. Due to its rarity, alexandrite is one of the most expensive gemstones in the world.

Synthetic alexandrite, which is less expensive, is often used as a substitute for the natural stone. However, there are several ways to distinguish between natural and synthetic alexandrite, such as examining the crystal structure.


Sapphire is a variety of corundum that is known for its deep blue color. However, some sapphires exhibit color-change properties, appearing blue in daylight and purple in incandescent light.

This is due to the presence of chromium and vanadium in the crystal structure.

Sapphires that exhibit color change are rare and highly valued.

Montana sapphires are known for their unique color change properties, but they are often less expensive than their blue counterparts.


Garnet is a diverse group of minerals that come in various colors, including red, orange, yellow, green, blue, purple, brown, and black. Some garnets also exhibit color-change properties, thanks to the intergrowth of spessartine and pyrope garnets.

Garnets that exhibit color change may appear green or blue in natural light, but under incandescent or fluorescent light, they may appear red or purple. This color-change phenomenon is due to the way the crystal absorbs and reflects light.


Zultanite is a registered trade name for a gemstone that originates from

Turkey. It is a rare variety of diaspore that exhibits remarkable color-change properties.

Zultanite may appear yellowish-green in daylight, but it changes to pinkish-red under incandescent light.

Zultanite is a unique gemstone that is often imitated by fakes. As such, it is important to source zultanite from trusted sources to ensure its authenticity.

One way to distinguish between genuine and fake zultanite is to examine it under a polarizing microscope. Fakes may also be made of dichroic glass.


Spinel is a historic gemstone that is often underappreciated compared to its ruby counterparts. However, some spinels exhibit remarkable color-change properties that make them unique.

Spinel may appear brownish-red in daylight, but under incandescent light, it appears purple. The color-change mechanism in spinel is still not well understood, but chemical analysis reveals that it contains traces of iron, magnesium, and chromium.

Properties of Gemstones

Apart from color-change properties, gemstones possess a range of other properties that make them unique and highly valued.


Color is one of the most important properties of a gemstone and often the first thing people notice. Gemstones come in a range of colors, from pink to blue to green to yellow.

The color of a gemstone is often due to the presence of impurities in its crystal structure.


Gemstones that are rare are often highly valued and expensive. For instance, alexandrite is one of the rarest gemstones, making it one of the most expensive.

Rarity is often determined by a variety of factors, including the availability of the gemstone and the difficulty of mining it.


The composition of a gemstone is another important property that makes it unique. For instance, chrysoberyl is a mineral that contains aluminum oxide and beryllium.

It is the only mineral that exhibits color-change properties. Corundum is another gemstone that is composed of aluminum oxide, but it can come in various colors, including blue, yellow, and pink.

The composition of a gemstone also plays a role in its durability and hardness.


Gemstones are fascinating and beautiful pieces of nature that exhibit a range of properties that make them unique and valuable. Some gemstones exhibit color-change properties, making them even more fascinating and highly sought after.

Understanding the properties of gemstones can help you identify and appreciate their beauty even more.

Pricing and Market

Gemstones are renowned for their beauty, rarity, and high demand, making them expensive and highly valued among enthusiasts, collectors, and investors. The price of a gemstone often varies based on several factors, including its rarity, quality, and market demand.


Gemstones can be enormously expensive, ranging from a few hundred dollars per carat to tens of thousands of dollars per carat. For instance, alexandrite, one of the rarest and most coveted gemstones, can fetch as much as $15,000 per carat for top-quality, natural specimens.

Mid-range alexandrite can still demand a price in the mid-five-figure range per carat. Similarly, sapphires with color-change properties are also relatively rare and expensive.

The price of such sapphires can exceed that of blue sapphires of equivalent size and quality.

Rarity and market demand determine the pricing of gemstones, with those in high demand commanding higher prices.

Fakes and Substitutes

Due to the high cost of natural gemstones, there are often synthetic or lab-created stones that can replicate the look of exotic gems such as alexandrite or zultanite. However, not all synthetic stones are of high quality, and some can be easily identified as fakes.

Dichroic glass is a popular substitute for some gemstones, and it can replicate the color-change properties and unique hues of rare stones. However, dichroic glass often has a bubbly texture that distinguishes it from real gemstones, which have a more natural, organic feel.

For those who simply cannot afford a natural gemstone, there are affordable alternatives on the market, such as cubic zirconia, which mimics the look of diamonds, or moissanite, which replicates the look of a natural emerald. While these stones lack the natural elegance and beauty of real gems, they are still attractive and durable while serving their budget-friendly purpose.

Market Value

Gemstones can possess a high market value, especially those that are rare, scarce, and limited in distribution. The market value of a gemstone is often determined by several factors, including the stone’s rarity, desirability, and demand among collectors, investors, and the general public.

For example, alexandrite and zultanite are relatively rare and have limited sources, making them highly sought after and valuable among collectors and enthusiasts.

Sapphire, on the other hand, is more readily available, but sapphires with color-change properties are rare, making them highly valued and sought after.

Regions and Producers

The origin of the gemstone often affects its rarity and value, with certain regions and producers being associated with particular types of gemstones.

Ural Mountains


Ural Mountains in Russia are known for being the primary supplier of alexandrite, one of the world’s rarest and most prized stones. This mineral was discovered in this region in the early 19th century.

This gemstone has a green hue under natural light, which changes to reddish-purple under incandescent light. This region continues to produce some of the most beautiful alexandrite stones in the world.


Montana is known for producing some of the finest sapphires in the world.

Sapphires from

Montana are highly prized for their deep blue color and color-change properties.

Montana sapphires are known for their unique color change properties, which can only be found in this region, making them highly valuable.


Zultanite is a relatively new gemstone that is only found in

Turkey. It’s a rare variety of diaspore that possesses breathtaking color-changing properties.

When viewed in daylight, it appears yellowish-green, and under incandescent light, it changes to pinkish-red. Its a registered trade name, and

Turkey is currently the sole producer of this unique gemstone.


The world of gemstones is filled with wonder, mystery, and beauty. From the rare and unique color-change properties of alexandrite to the affordable alternatives like cubic zirconia, there is a gemstone for everyone.

The value of a gemstone is determined by many factors, such as rarity, quality, and market demand. By understanding these facets of gemstones, enthusiasts, collectors, and investors can appreciate the unique properties of these precious stones and their worth.

Mechanisms and


The fascinating world of gemstones is not only about the beauty and rarity, but also about the mechanisms that make some of them so unique. Understanding these mechanisms and phenomena can help us appreciate the unique properties of each gemstone.


The properties of a gemstone are often determined by the way light interacts with its crystal structure. The absorption and transmission of photons by the atoms within the crystal can lead to a wide range of optical effects.

The way a gemstone absorbs and reflects light determines its color, clarity, and brilliance. For instance, the color change effect observed in certain gemstones occurs due to the different absorption of light at different wavelengths.

The presence of certain impurities in a crystal, such as chromium or vanadium, can lead to color-change properties in sapphires and garnets. The intergrowth of crystals can also lead to unique phenomena such as the color change effect observed in some garnets.

For instance, a portion of the garnet crystal may be rich in magnesium while another portion is rich in iron, leading the crystal to display different colors with different angles of light. The way our eyes perceive color is a crucial part of the mechanisms that govern the properties of a gemstone.

Light enters the eye and excites the photoreceptor cells within the retina. The brain then interprets the combination of signals from these cells to produce the sensation of color.


Exposure to various lighting conditions can showcase a gemstone’s unique properties, leading to a variety of phenomena. Lighting can affect the color of a gemstone, causing it to appear different colors under different light sources.

For instance, alexandrite appears to be green in daylight but can exhibit a reddish-purple color change under incandescent light. This shift in color can be dramatic and captivating, making it a prized gemstone among collectors and enthusiasts.

Similarly, a gemstone may appear to be one color in fluorescent lighting conditions and another color in natural daylight. This phenomenon is commonly observed in some garnets, which can appear green under natural light but then appear pink or purple in fluorescent lighting conditions.

Artificial lighting, such as that found in jewelry store displays, can often create a range of different color effects. Sometimes, light is strategically directed at a gemstone in such a way that it appears to “glow” or “sparkle.” This is commonly observed in diamonds, where the stones’ many facets capture the light and reflect it back at the viewer, creating a brilliant and eye-catching effect.

In other cases, artificial lighting can actually diminish some gemstones’ beauty or make them appear dull or lifeless. This is why it is crucial to examine gemstones in a variety of lighting conditions before making a purchase.


Gemstones are truly remarkable creations of nature that exhibit a vast range of mechanisms and phenomena. Understanding these elements can help us appreciate the unique properties and beauty of each gemstone, and also enable us to identify and authenticate them correctly.

Factors such as exposure to different light sources and the intergrowth of crystals all contribute to the remarkable range of optical effects that can be observed in gemstones. These fascinating phenomena continue to captivate collectors, enthusiasts, and jewelry lovers all over the world.

Gemstones are a unique and fascinating creation of nature that possess a range of properties and mechanisms that make them highly sought after and valuable. From the color-changing properties of alexandrite and sapphire to the phenomena observed in different lighting conditions, each gemstone has its unique qualities.

Understanding these elements is crucial to appreciate the beauty and rarity of gemstones. FAQs:

Q: What makes a gemstone valuable?

A: Factors such as rarity, quality, and market demand determine the value of a gemstone. Q: Are synthetic gemstones just as valuable as natural ones?

A: Synthetic gemstones are typically less valuable than natural ones but may be valuable due to unusual or desirable properties. Q: How can you identify fake gemstones?

A: Fakes are often identifiable by their low-quality appearance and lack of natural organic texture. Q: What kind of lighting should you use to view a gemstone?

A: It is best to view a gemstone in natural light, as artificial lighting can impact a gemstone’s appearance. Q: What are some affordable alternatives to natural gemstones?

A: Cubic zirconia and moissanite are popular alternatives to natural gemstones. Q: Why are gemstones with color change effects valuable?

A: The color-changing properties are rare and make the gemstones unique and highly sought after.

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