Sapphires are one of the most beloved gemstones in the jewelry industry, known for their vibrant blue hues and exceptional durability. However, many sapphire owners have noticed that their sapphires may appear purple under certain lighting conditions. This phenomenon can be surprising to those unfamiliar with the gem’s color properties. In this article, we will explore the reasons why a sapphire might look purple and how these changes in appearance occur. We will also cover the factors that contribute to the color of sapphires and the potential for purple variations in these gemstones.
The Science Behind Sapphire Color
To understand why sapphires may look purple, it’s essential to first examine the science of sapphire color. Sapphires belong to the corundum family, a group of gemstones that come in a variety of colors, from blue and pink to yellow, green, and even purple. The primary factor that determines the color of a sapphire is the trace elements that are present during its formation. When a sapphire is formed, specific elements such as iron, titanium, and chromium can influence the final hue of the gemstone.
In a traditional blue sapphire, titanium and iron combine to create the iconic blue color. However, if there are additional trace elements, such as trace amounts of chromium, the sapphire might exhibit a reddish or purplish tint. This effect is known as pleochroism, which refers to the ability of a gemstone to display different colors when viewed from different angles.
Pleochroism in Sapphires
Pleochroism is a characteristic of many gemstones, including sapphires. This optical phenomenon causes the gemstone to appear in different colors depending on the angle from which it is viewed. A sapphire that appears blue from one direction may show purple or violet hues when viewed from another angle. This change in color can be subtle or pronounced, depending on the sapphire’s composition and the lighting conditions.
When a sapphire contains a mix of iron, titanium, and chromium, the pleochroism effect can be more dramatic. The result is that the gemstone may shift between blue and purple as the angle of viewing changes. In some cases, sapphires with a more significant amount of chromium may even appear primarily purple, particularly under certain lighting conditions.
Lighting Conditions and Purple Sapphire
Lighting plays a significant role in how sapphires appear. Natural daylight, incandescent light, and fluorescent light all emit different wavelengths of light, which can affect how the colors in a gemstone are perceived. Sapphires can appear to be a range of colors depending on the type of light they are exposed to.
Under incandescent light, which has a warmer tone, sapphires may take on a purplish or reddish hue. This is because the warmer light enhances the reddish and violet tones in the gemstone. Conversely, under fluorescent light, which tends to have a cooler, bluish tone, the blue characteristics of the sapphire may be more prominent, making it look less purple.
Sapphire Treatment and Color Change
In some cases, sapphires are treated to enhance their color. One common treatment is heat treatment, which involves exposing the gemstone to high temperatures to improve its hue and clarity. Heat treatment can also intensify the blue color of a sapphire, but it may also cause the stone to exhibit purple tones, depending on the conditions under which the treatment is performed.
Another treatment method is the use of radiation to enhance the color of the sapphire. This process can sometimes cause a sapphire to shift in hue, making it appear more purple. While treatments can affect the color of sapphires, it’s essential to note that these changes are typically stable and do not significantly alter the gemstone’s value if properly disclosed.
The Rarity of Purple Sapphires
While sapphires are most commonly associated with blue, purple sapphires are considered relatively rare and unique. Natural purple sapphires are a blend of blue and violet hues, and their color can range from a pale lavender to a deep, rich purple. The presence of chromium, along with the sapphire’s pleochroic properties, is what gives these sapphires their distinctive purple appearance.
Purple sapphires have gained popularity in recent years due to their rarity and the growing interest in colored gemstones. These sapphires can make stunning centerpieces for engagement rings, necklaces, and earrings, offering a bold and sophisticated alternative to traditional blue sapphires.
How to Identify a Purple Sapphire
Identifying a purple sapphire can sometimes be challenging, especially if the gemstone is viewed under different lighting conditions. However, there are a few ways to determine whether your sapphire is truly purple or simply displaying purple hues due to pleochroism.
Examine the color in different lighting: As mentioned, lighting plays a significant role in how sapphires appear. Take your sapphire into natural daylight, incandescent light, and fluorescent light to see how the color changes.
Consider the hue and saturation: Purple sapphires typically have a rich blend of blue and purple tones. If your sapphire appears more violet or reddish than blue, it may be a purple sapphire.
Consult a professional: If you’re unsure about the color of your sapphire, a certified gemologist can assess the stone and provide a detailed analysis. They can use specialized tools, such as a spectroscope, to examine the gemstone’s color properties.
Conclusion
Sapphires are fascinating gemstones that exhibit a wide range of colors and hues, including shades of purple. The appearance of purple in a sapphire can result from a combination of pleochroism, trace elements, lighting conditions, and gemstone treatments. While most sapphires are associated with blue, purple sapphires offer a unique and striking alternative that has gained popularity among gemstone enthusiasts. Whether your sapphire is naturally purple or displaying purple hues due to its pleochroic nature, it’s essential to understand the factors that contribute to its color.
Understanding why your sapphire looks purple can enhance your appreciation of the gemstone’s beauty and provide insight into its formation and characteristics.
Related topics:
- Do Sapphires Look Good with Yellow Gold?
- Discover Where Sapphires Are Found: A Complete Guide
- Which Shape of Yellow Sapphire is the Best?
