Gemstones commonly referred to as jade can, in fact, be one of two distinct minerals, jadeite and nephrite. They have similar outward appearances but different internal structures and properties. Jadeite is the rarer and harder stone. It's well suited for intricate carvings and cabochons. Although jadeite has a popular association with green, it can be found in many colors. However, the rich emerald-green color of “imperial jade” is the most highly valued. Historically, Chinese, Meso-American, and Maori cultures have revered jadeite and created exquisite works of art with this material. Today, the Chinese market and admiration for jadeite remains strong.
The value of a jadeite carving is as much a function of artistry and antiquity as the color and quality of the material itself. Jadeite is a very specialized gemstone, and evaluating these pieces is complicated. Its market is largely collector based. The finest jadeite originates from Myanmar. (As of 2016, jadeite from Myanmar is subject to a US embargo).
The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.
|Is a Variety of||Jade|
|Alternate Common Names||Jade|
|Crystallography||Monoclinic. Crystals very rare and tiny, usually granular with tough, interlocked crystals: fibrous; as alluvial boulders and pebbles.|
|Refractive Index||Jadeite 1.64 - 1.667|
|Colors||Colorless, white, all shades of green, yellow-green, yellowish brown, brown, red, orange, violet (mauve), blue (rare), gray, black|
|Polish Luster||Vitreous to greasy|
|Hardness||6.5 - 7|
|Specific Gravity||Jadeite 3.25 - 3.36, usually 3.34+|
|Cleavage||None (massive). Very tough.|
|Luminescence||Pale colors may show dim white glow in LW. No reaction in SW. X-rays may give intense blueviolet glow in pale yellow and mauve stones.|
|Spectral||See "Identifying Characteristics" below.|
|Enhancements||See "Enhancements" below.|
|Special Care Instructions||None|
|Transparency||Opaque to translucent|
|Optics||a = 1.640, β= 1.645, γ= 1.652-1.667. Shadow edge usually 1.66. Biaxial (+), 2V = 67°.|
|Etymology||From jade. The term jade comes from the Spanish piedras de ijada, “stone of the loins.” Jade was believed to heal kidney ailments.|
|Occurrence||Chiefly in serpentine derived from olivine rocks. Also as alluvial boulders.|
Jade has been used to make jewelry and weapons since prehistoric times. There are many legends and strong cultural associations with jade gemstones. The Chinese sage Confucius compared jade to a gentleman esteemed by all for his qualities. The Chinese have traditionally valued jade for carving as well as religious and medicinal purposes. The Olmecs, Maya, and Aztecs of Meso-America made ceremonial objects and jewelry from jadeite. They valued this material more than gold. The Aztecs characterized eloquence as “a scattering of jades.” The Maori of New Zealand created weapons as well as heirloom ornaments from jadeite called hei-tiki.
Jade is the hour birthstone for those born between 9 and 10 PM.
Jadeite can be found in many colors, but green is in great demand. “Imperial jade” of deep green color from Myanmar is very rare and expensive. Apple green and lavender or mauve colors are also popular. Translucent material is highly prized. Green boulders may have a brown skin due to weathering. These are often used for carving. The colors in this stone can sometimes have a mottled look. Crystals are very rare.
|Green Jadeite Color Terminology|
|Apple Green||New Mine or Flower Green|
Jadeite is a mineral in the pyroxene group. It can combine with other minerals from this group in solid solutions. Jadeite may be present in these blends, but they are not always described as jadeite varieties.
- Omphacite may contain jadeite, augite, and aegirine.
- Maw sit sit is a rock found only near the Myanmar village it’s named after. It has a dark green color with black spots and green veins. Some specimens have been found containing jadeite, kosmochlor (sometimes called ureyite), albite feldspar, and other minerals.
- Stone made almost entirely of jadeite is called jadeitite.
Jadeite has a distinctive spectrum useful in identification. There is a strong line at 4375 and weak bands at 4500 and 4330. The 4375 line is diagnostic but may not be seen in rich, deep green material, which has a chromium spectrum: strong line at 6915, weak at 6550 and 6300.
Jadeite has been synthesized in the laboratory. The results have similar refractive index, specific gravity, absorption spectra, and fluorescence to natural stones. They have greater hardness, up to 8, and color and texture difference, however. These synthetics are not commercially available.
There are, however, many simulants on the market. Some natural gemstones that may be passed off as jade are calcite, green idocrase (erroneously referred to as “American jade”), aventurine (erroneously referred to as “Indian jade”), serpentine (erroneously referred to as “Korean jade”), and green hydrogrossular garnet (erroneously referred to as “Transvaal jade”). Green-dyed marble can be found sold as “Mexican jade.” See our List of False or Misleading Gemstone Names for more examples.
Glass and plastic can also be used to simulate jade.
Gray material can be stained to resemble “imperial jade” or dyed to take on a mauve color. Bleaching, or acid treatments, and wax impregnation are occasionally used to improve color and luster. Polymer coatings are stable treatments.
- Myanmar: source of “imperial jade.”
- Guatemala: rare blue stones.
- Russia: apple green-colored material at some localities; also fine translucent, Cr-rich material at the Kantegir River, West Sayan.
- Bursa, Turkey: purple Turkish jade, a jadeite/quartz rock, unique to this location.
- San Benito County, California: lenses and nodules in chert, various colors, also mixed with nephrite.
- New Zealand; Japan; Mexico.
Jade pieces are tough. They are not the hardest stones on the Mohs scale (which only measures resistance to scratching) but are very resistant to breaking. Their wearability is excellent. Natural, untreated stones may withstand mechanical cleaning. However, acid treatments can create cracks in an otherwise very durable material. If you’re unsure if your jewelry or carving has been treated, stick to warm water, detergent, and a soft brush. Consult our Gemstone Care Guide and Gemstone Jewelry Cleaning Guide for more recommendations.