The idea that jade is exclusively green is a common misunderstanding. In reality, jade occurs across a wide spectrum of colors, including lavender, yellow, black, and a highly prized white. White jade has been historically significant, especially in China, where it was revered for its purity. For centuries, it was used in ceremonial objects and imperial carvings. This color variation confirms that jade is defined by its mineral structure, not just its hue.
Defining the Two Mineral Forms of Jade
The term “jade” is a cultural designation that scientifically refers to one of two distinct silicate minerals: nephrite and jadeite. Nephrite is a calcium and magnesium silicate, classified as an amphibole mineral, which forms a dense, interwoven fibrous structure. Jadeite is a sodium and aluminum silicate belonging to the pyroxene group, characterized by a granular crystal structure. Both mineral types can manifest in a white coloration.
Nephrite is the form of jade historically used in ancient China and is commonly found in large deposits that yield white material. The white form of nephrite is often composed primarily of the mineral tremolite. While pure white jadeite also exists, it is generally rarer and commands a higher value in its most translucent grades.
The Chemical Basis for White Coloration
The presence or absence of specific trace elements determines jade’s color. White jade represents the material in its purest form. Green jade is typically colored by chromophores, trace impurities such as chromium or iron ions. White jade, by contrast, is essentially colorless because it lacks these metallic trace elements in sufficient concentration to produce a hue.
A highly valued type of white nephrite is known as “Mutton Fat Jade,” named for its creamy color and characteristic sheen. This variety possesses a unique appearance due to its tightly packed microcrystalline structure. The dense, interlocking network of crystals disperses light, giving the material a desirable, semi-translucent quality. This results in a soft, oily or waxy luster, rather than a glassy or chalky look.
Characteristics of High-Quality White Jade
The value and authenticity of white jade are determined by several key characteristics. Translucency is a significant factor, with the best pieces allowing light to pass through with a gentle, misty glow, ranging from semi-translucent to opaque. The surface should exhibit a distinctive luster, often described as greasy, oily, or waxy, especially in nephrite. High-quality pieces display excellent uniformity, with a consistent color and texture free from noticeable inclusions or veining.
Because white jade is highly sought after, it is frequently imitated by simulants such as white quartz, glass, or marble. Simple tests can help distinguish genuine jade from these alternatives. Authentic jade is a dense material that feels significantly colder to the touch than glass or plastic and takes longer to warm up when held. Its high density also means genuine jade will feel heavier than a piece of quartz or glass of the same size. Jade has a high Mohs hardness, between 6 and 7, meaning it should not be easily scratched by a steel knife.