Amethyst is a popular purple variety of quartz, prized for its captivating color. However, some amethyst pieces can appear to lose their color, becoming faded or exhibiting a whitish appearance over time.
Understanding Amethyst’s Characteristic Color
Amethyst’s distinctive purple color originates from trace amounts of iron impurities within its quartz crystal structure. Natural irradiation interacts with these iron impurities, creating “color centers” within the crystal. These centers are responsible for absorbing specific wavelengths of light, producing the characteristic purple hue.
Primary Causes of Amethyst Fading
Prolonged exposure to direct sunlight or strong ultraviolet (UV) light is a common reason amethyst loses its vibrant purple color. High-energy UV radiation disrupts the color centers within the crystal. This degradation reduces the stone’s ability to absorb light, resulting in a faded or brownish-yellow appearance.
High temperatures also significantly impact amethyst’s color. When heated to temperatures typically ranging from 750 to 900 degrees Fahrenheit (400 to 500 degrees Celsius), the color centers responsible for the purple hue become unstable and break down. This process causes the amethyst to lose its purple coloration, transforming it into yellow, orange, or even colorless quartz. This temperature-induced color change is sometimes intentionally used in the gem industry to produce citrine, which is a yellow-orange variety of quartz, from amethyst.
Beyond light and heat, certain chemical exposures can also affect amethyst’s appearance. While the quartz structure is relatively stable, harsh chemicals can potentially react with the stone’s surface or even penetrate minor fractures. Strong cleaning agents, acids, or prolonged contact with substances like hairspray, perfumes, or lotions may dull the stone’s luster or alter its surface characteristics, making the color appear less intense.
Other Reasons for a Whitish Appearance
Amethyst can develop a whitish appearance due to surface damage. Physical abrasion, such as rubbing against harder materials or accidental impacts, can create tiny scratches and scuffs on the stone’s polished surface. These microscopic imperfections scatter light rather than allowing it to pass through cleanly, which can make the amethyst look dull, frosted, or give it a hazy, whitish sheen.
Internal characteristics of the amethyst crystal can also contribute to a whitish or cloudy look. Natural inclusions, which are small foreign materials or gas bubbles trapped within the crystal during its formation, can refract and scatter light. Similarly, internal fractures, which are tiny cracks within the stone, can also scatter light, making the amethyst appear less clear. If these inclusions or fractures become more prominent due to stress or minor impacts, they can make the stone appear cloudier or even whitish from within.
Accumulation of surface residue is another common reason for amethyst appearing whitish or dull. Everyday substances like dirt, dust, soap scum, body oils, or residues from lotions and cosmetics can build up on the stone’s surface, especially in jewelry settings. This layer of grime can obscure the amethyst’s natural color and luster, giving it a cloudy, whitish film. Regular and appropriate cleaning can often restore the stone’s original brilliance.
Protecting Your Amethyst
To preserve amethyst’s rich purple color, it is important to store it away from direct sunlight and intense artificial light sources. Keeping amethyst out of direct sunlight, especially windows, and away from heat sources like radiators or hot cars, helps prevent the degradation of its color centers. Consistent exposure to light and heat can cumulatively affect the stone’s hue over time.
When cleaning amethyst, use only mild soap and lukewarm water. A soft brush can gently remove surface dirt without causing abrasion. It is advisable to avoid harsh chemical cleaners, abrasive materials, and ultrasonic cleaners, as these can potentially damage the stone. After cleaning, rinse the amethyst thoroughly with clean water and dry it with a soft, lint-free cloth.
Storing amethyst properly also helps protect it from damage. Keep amethyst jewelry and loose stones in a soft cloth pouch or a fabric-lined jewelry box. This practice prevents the amethyst from rubbing against harder gemstones or metal components that could scratch its surface. Separating amethyst from other pieces helps maintain its polished finish and prevents a dull, whitish appearance from surface abrasions.
Wearing amethyst jewelry mindfully can also extend its lifespan and maintain its appearance. Consider removing amethyst rings or bracelets before engaging in activities that might expose them to impacts, such as sports or manual labor. Similarly, remove amethyst jewelry before applying lotions, perfumes, or hairsprays, as these products can leave residues or contain chemicals that might dull the stone over time.