The term “jade” refers to two distinct minerals, one of which is jadeite. Jadeite is a pyroxene mineral prized for its vibrant colors and high polish, making it the more sought-after type for fine jewelry. Identifying genuine, high-quality jadeite can be complex, as it appears in a wide range of natural forms and is frequently imitated or treated. Understanding its specific visual and physical characteristics is necessary to distinguish the real thing from its many look-alikes.
The Spectrum of Natural Appearance
Jadeite’s natural coloration spans a broad spectrum, though it is most famous for intense shades of green. The most prized color is “Imperial Green,” an emerald-like hue with high translucency caused by trace amounts of chromium. Other natural colors include lavender, ranging from pale lilac to deep violet, and yellow to reddish-orange hues resulting from iron oxidation.
The stone’s transparency, known as its “texture” in the jade trade, is a significant factor in its appearance and value. Jadeite ranges from opaque to highly translucent or “icy,” where light appears to penetrate deep into the stone. This translucency, especially when paired with strong color, makes the stone appear to glow, which increases its desirability. When polished, jadeite exhibits a vitreous, or glass-like, luster.
Physical Characteristics Beyond the Surface
Jadeite possesses distinct physical properties that contribute to its identity and feel. It is a dense material, with a specific gravity typically ranging from 3.30 to 3.38, which is higher than many common simulants. This density gives genuine jadeite a satisfying “heft,” making it feel substantial and heavier than expected for its size. Jadeite also has a Mohs hardness of 6.5 to 7.0, meaning it is relatively hard and durable. Its toughness, or resistance to chipping and breaking, is exceptional due to its structure as an aggregate of interlocking crystals, and it is a poor conductor of heat, so it feels cool to the touch.
Differentiating Jadeite from Look-Alikes
The primary distinction is between jadeite and nephrite, as both are classified as “jade.” They are chemically different minerals, which gives jadeite a more glass-like luster, while nephrite tends to have a waxier appearance. Jadeite is also slightly denser and harder than nephrite, which has a Mohs hardness of 6.0 to 6.5. Beyond nephrite, many other materials are used as simulants, including dyed quartz, serpentine, and glass. Glass fakes often reveal small gas bubbles under magnification, and dyed materials frequently display an unnaturally uniform color.
Understanding Enhanced and Treated Jadeite
Even if a stone is confirmed to be jadeite, its appearance may have been altered through various treatments, which significantly affect its value. These treatments are categorized into a system of A, B, and C types. Only Type A is considered natural jadeite and retains long-term value.
Type A
Type A jadeite is natural and only polished, with waxing considered an acceptable surface finish that does not alter the stone’s internal structure.
Type B
Type B jadeite has been chemically treated by soaking it in strong acid to remove impurities, improving its transparency. The resulting porous material is then filled with a polymer resin to stabilize its structure and enhance its luster.
Type C
Type C jadeite has been artificially colored with dye to achieve a more vibrant hue, often in addition to the Type B treatment. The dye often pools along the crystalline grain boundaries, creating an unnatural color that can fade over time.