How to identify Jade

To correctly identify Jade (Jade (Nephrite or Jadeite)), check each of these features in order. Many rocks and minerals look alike, so cross-reference multiple properties before deciding.

Step-by-step identification

1. 1

   Color

   Overall color and any zoning or banding

   Nephrite: Typically creamy white, spinach green, dark green, grey, or black. Jadeite: More vibrant and diverse colors including emerald green (imperial jade), lavender, white, yellow, orange, brown, and black.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Both typically exhibit a greasy to vitreous luster when polished, dull to waxy on rough surfaces.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Both are microcrystalline, resulting in a very fine-grained, compact, and interlocking fibrous (nephrite) or granular (jadeite) texture. This contributes to their exceptional toughness.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Nephrite: Cryptocrystalline aggregate of interlocking fibrous amphibole crystals. Jadeite: Cryptocrystalline aggregate of interlocking granular pyroxene crystals.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   Nephrite: No distinct cleavage in massive form due to its interlocking fibrous nature, but individual amphibole crystals have two perfect cleavages at 56° and 124°. Jadeite: No distinct cleavage in massive form, but individual pyroxene crystals have two good cleavages at nearly 90°.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Nephrite: Serpentinized ultramafic rocks, often in contact with felsic intrusions or in shear zones. Jadeite: High-pressure, low-temperature metamorphic rocks (blueschist facies), often associated with serpentinite in subduction zone mélanges.

Key Facts

Hardness

Nephrite: 6-6.5 on Mohs scale. Jadeite: 6.5-7 on Mohs scale.

Specific Gravity

Nephrite: 2.90-3.10. Jadeite: 3.30-3.50.

Crystal System

Nephrite: Monoclinic. Jadeite: Monoclinic.

Color

Green, white, lavender, yellow, black, grey, orange, brown.

Luster

Greasy to vitreous.

Transparency

Opaque to translucent, rarely semi-transparent.

Fracture

Splintery (nephrite), granular to splintery (jadeite). Both exhibit exceptional toughness.

Cleavage

Nephrite: No distinct cleavage in massive form. Jadeite: No distinct cleavage in massive form.

Composition

Nephrite: Ca2(Mg,Fe)5Si8O22(OH)2 (calcium magnesium iron silicate). Jadeite: NaAlSi2O6 (sodium aluminum silicate).

Physical characteristics

• Crystal Habit: Nephrite: Cryptocrystalline, interlocking fibrous aggregates. Jadeite: Cryptocrystalline, interlocking granular aggregates.
• Cleavage Type: None observed in massive material due to microcrystalline nature; individual crystals have perfect (nephrite) or good (jadeite) cleavage.
• Fracture Type: Splintery to conchoidal (nephrite), granular to splintery (jadeite). Extremely tough.
• Tenacity: Extremely tough (resistant to breaking and chipping).
• Luster Type: Greasy to vitreous.

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