Jade has been a treasured material for centuries, valued for its durability and stunning range of colors, from deep greens to delicate lavenders. Owners of jade jewelry and art often wonder if sun exposure can lead to color fading. This concern is understandable given the stone’s value and the common instability of many colored materials when exposed to ultraviolet (UV) light. The reality of jade’s environmental stability depends entirely on the stone’s geological composition and whether it has undergone commercial treatments.
Natural Jade’s Resistance to Light
Untreated, natural jade possesses inherent stability, making it highly resistant to the effects of light and sun exposure. The color within natural jade is not due to delicate organic pigments but rather to trace elements like chromium and iron chemically locked within the stone’s structure. Because these elements are an intrinsic part of the silicate mineral, they do not react to UV radiation in a way that causes bleaching or fading.
The mineral’s dense, microcrystalline structure contributes to its color permanence and toughness. This geological formation ensures the color is chemically stable and physically protected from external factors like typical sun exposure. While extreme, prolonged heat can sometimes cause minor surface dehydration, the stone’s color will remain unaffected by the temperatures encountered during normal wear or display.
The Two Types of Jade
The term “jade” is a cultural name that encompasses two distinct mineral species: Jadeite and Nephrite. Jadeite is a sodium aluminum silicate, often prized for its vibrant, glassy appearance and wide color spectrum. Its hardness is slightly higher, ranking between 6.5 and 7 on the Mohs scale, characteristic of its compact, granular crystalline structure.
Nephrite is a calcium magnesium iron silicate and is classified as an amphibole mineral. Although slightly softer, measuring between 6 and 6.8 on the Mohs scale, it is renowned for its exceptional toughness. This durability results from its unique fibrous, interwoven crystal structure.
Why Treated Jade Fades
The perception that jade fades originates almost entirely from the behavior of treated stones. Lower-quality jadeite is often subjected to commercial treatments, commonly labeled B, C, or B+C, to enhance its appearance.
B-jade is acid-bleached to remove impurities and then impregnated with a polymer or resin to fill fissures and improve translucency. This polymer filler, essentially a plastic, degrades when exposed to UV light and heat, not the natural stone itself. Over time, UV radiation causes the polymer to break down and oxidize, leading to an unsightly yellowing or dulling of the stone’s overall appearance.
C-jade, or dyed jade, has been artificially colored using chemical dyes forced into the crystal fissures. These dyes are not chemically stable, and prolonged exposure to sunlight will cause them to bleach out. This irreversible color loss is a failure of the artificial enhancement, confirming the treatment is unstable under environmental conditions.
Handling and Storage Recommendations
To ensure the longevity of any jade object, especially treated pieces, focus on minimizing exposure to environmental stressors. Direct and prolonged exposure to sunlight should be avoided to prevent the degradation of polymer fillers or the bleaching of artificial dyes. This protection is important for jewelry worn outdoors or items displayed near sunny windows.
Cleaning Jade
Cleaning jade requires a gentle approach to avoid damaging surface polishes or treatments. The stone should be cleaned using only mild soap and tepid water, and dried with a soft cloth. Harsh chemicals, such as household detergents, alcohol, or acetone, can chemically attack and break down the polymer resins used in treated jade.
Storage
For long-term storage, jade should be kept in a dark, temperature-stable environment. It should be separated from harder gemstones that could scratch its surface.