Turquoise, with its captivating hues ranging from sky blue to green, has been treasured for thousands of years for its beauty and supposed metaphysical properties. However, turquoise owners sometimes notice a distressing change: their vibrant stone starts turning white. This alteration can be alarming, especially for those who cherish their turquoise jewelry or collect stones for their historical and cultural significance. Understanding why this happens requires delving into the composition of turquoise, its environmental sensitivities, and proper care practices.
The Composition of Turquoise
To understand why turquoise changes color, we first need to explore its composition. Turquoise is a hydrous phosphate of copper and aluminum, with the chemical formula CuAl6(PO4)4(OH)8·4H2O. The vibrant blue and green colors of turquoise are primarily due to the presence of copper.
Natural Variability
Turquoise forms through the interaction of percolating groundwater with minerals containing copper and aluminum. This natural process can create significant variability in the composition of turquoise, influencing its color, hardness, and overall stability. Some turquoise stones may have a higher copper content, while others may contain more iron, which can impart a greener hue. This inherent variability means that no two pieces of turquoise are exactly alike, making each piece unique but also leading to differences in how they react to environmental conditions.
Environmental Factors Affecting Turquoise
Turquoise is a relatively soft and porous gemstone, with a Mohs hardness of around 5-6. This means it is susceptible to damage and alteration from environmental factors such as moisture, oils, chemicals, and physical abrasion.
Exposure to Moisture and Oils
One of the primary reasons turquoise can turn white is exposure to moisture and oils. Because turquoise is porous, it can easily absorb liquids from its environment. Over time, the absorption of water, oils from the skin, lotions, perfumes, and other substances can cause the stone to change color.
Moisture Absorption
When turquoise absorbs water, it can cause the stone to swell slightly. This swelling can lead to the breakdown of the internal structure of the stone, causing a change in its color and making it appear lighter or whitish.
Oils and Lotions
Oils from our skin or from lotions and perfumes can also penetrate the surface of turquoise. These substances can create a film over the stone, dulling its natural luster and causing a whitish or yellowish tint. Over time, the oils can interact with the minerals in the turquoise, leading to more permanent color changes.
Chemical Exposure
Turquoise is sensitive to various chemicals, including household cleaners, chlorine, and even acidic sweat. These chemicals can cause reactions with the minerals in the turquoise, leading to discoloration.
Household Cleaners
Many household cleaners contain harsh chemicals that can damage the surface of turquoise. For example, ammonia and bleach can cause the stone to fade or turn white by breaking down the chemical bonds within the stone.
Chlorine
Chlorine, commonly found in swimming pools and hot tubs, can be particularly harmful to turquoise. Prolonged exposure to chlorine can cause the stone to lose its vibrant color and turn white or pale.
Physical Abrasion
As a relatively soft stone, turquoise is prone to scratching and chipping. Physical abrasion from everyday wear or improper cleaning methods can damage the surface of the stone, causing it to lose its luster and appear whiter.
See Also: Who Can Wear Turquoise?
Turquoise Treatments and Stabilization
Given its sensitivity, many turquoise stones on the market undergo treatments to enhance their durability and appearance. Understanding these treatments can provide insight into why some turquoise stones might turn white over time.
Stabilization
Stabilization is a common treatment for turquoise. This process involves impregnating the porous stone with a clear resin or plastic to improve its hardness and durability. Stabilized turquoise is less likely to absorb moisture and oils, making it more resistant to color changes. However, if the stabilization treatment is poor or if the resin begins to degrade, the stone may still turn white.
Dying and Waxing
Some turquoise stones are dyed to enhance their color. While this can produce vibrant, uniform colors, the dyes can fade over time, especially with exposure to sunlight or chemicals. Additionally, waxing is sometimes used to enhance the luster of turquoise. Over time, the wax can wear off, revealing the true, often lighter color of the stone beneath.
Proper Care for Turquoise
To prevent turquoise from turning white, it is essential to take proper care of the stone. Here are some tips to help maintain the color and luster of your turquoise jewelry:
Avoid Exposure to Chemicals
Keep turquoise away from harsh chemicals, including household cleaners, chlorine, and perfumes. When cleaning your home, it’s a good idea to remove turquoise jewelry to avoid accidental exposure. If you swim regularly in chlorinated pools, consider removing turquoise jewelry beforehand.
Limit Contact with Water and Oils
Minimize the stone’s exposure to water and oils. Remove turquoise rings and bracelets when washing hands or applying lotions. Avoid wearing turquoise jewelry in the shower or while swimming.
Proper Storage
Store turquoise jewelry in a dry, cool place. Use a soft cloth or jewelry pouch to protect the stone from scratches and physical damage. Avoid storing turquoise with harder gemstones that could scratch its surface.
Gentle Cleaning
Clean turquoise jewelry gently using a soft, damp cloth. Avoid using commercial jewelry cleaners, ultrasonic cleaners, or steam cleaners, as these can damage the stone. If more thorough cleaning is needed, use mild soap and water, then dry the stone immediately and thoroughly.
Regular Inspections
Periodically inspect your turquoise jewelry for signs of damage or color change. If you notice any issues, consider consulting a professional jeweler who specializes in turquoise to assess the stone and recommend appropriate care or restoration measures.
Conclusion
The enchanting beauty of turquoise is matched only by its sensitivity to environmental factors. The stone’s tendency to turn white can be distressing, but understanding the reasons behind this change is the first step in preventing it. Turquoise is a hydrous phosphate mineral that can absorb moisture and oils, leading to color changes. Exposure to chemicals and physical abrasion can also cause discoloration and damage.
Treatments like stabilization can enhance the durability of turquoise, but proper care is still essential to maintaining its vibrant color. By avoiding exposure to harsh chemicals, limiting contact with water and oils, storing the stone properly, and cleaning it gently, you can help preserve the beauty of your turquoise for years to come.
In the end, turquoise is a testament to the wonders of nature, each stone telling a unique story through its color and composition. With the right care and attention, your turquoise can remain a cherished part of your collection, continuing to captivate and inspire.
