How to identify Jade

To correctly identify Jade (Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2) or Jadeite (NaAlSi2O6)), 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, various shades of green (spinach green, dark green), grey, brown, black. Jadeite: Wider range of colors including white, apple green, emerald green, lavender, blue, pink, yellow, orange, brown, black. Imperial jadeite is a vibrant, translucent emerald green.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Vitreous to greasy, sometimes waxy.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Typically fine-grained, compact, and dense. Can appear smooth or slightly granular.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Nephrite: Cryptocrystalline, interlocking fibrous aggregates (felted texture). Jadeite: Cryptocrystalline, interlocking granular aggregates.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   Nephrite: Perfect prismatic cleavage (two directions at 56° and 124°), but rarely observed due to fibrous nature. Jadeite: Perfect prismatic cleavage (two directions at 87° and 93°), also rarely observed in massive forms.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Nephrite: Serpentinized ultramafic rocks, contact metamorphic zones, often associated with tremolite-actinolite schists. Jadeite: High-pressure, low-temperature metamorphic rocks (blueschist facies), typically in serpentinite-rich environments within subduction zones.

Key Facts

Hardness

Nephrite: 6-6.5 (Mohs). Jadeite: 6.5-7 (Mohs).

Specific Gravity

Nephrite: 2.90-3.03. Jadeite: 3.30-3.38.

Crystal System

Nephrite: Monoclinic. Jadeite: Monoclinic.

Color

Nephrite: White, cream, various greens, grey, brown, black. Jadeite: White, apple green, emerald green, lavender, blue, pink, yellow, orange, brown, black.

Luster

Vitreous to greasy, waxy.

Transparency

Opaque to translucent, rarely semi-transparent.

Fracture

Splintery (nephrite), granular to splintery (jadeite).

Cleavage

Nephrite: Perfect prismatic (two directions at 56° and 124°), but rarely observed due to fibrous nature. Jadeite: Perfect prismatic (two directions at 87° and 93°), also rarely observed in massive forms.

Composition

Nephrite: Calcium magnesium iron silicate hydroxide. Jadeite: Sodium aluminum silicate.

Physical characteristics

• Crystal Habit: Nephrite: Dense, compact, interlocking fibrous aggregates (felted texture). Jadeite: Dense, compact, interlocking granular aggregates.
• Cleavage Type: Nephrite: Perfect prismatic, but typically not visible in massive forms. Jadeite: Perfect prismatic, typically not visible in massive forms.
• Fracture Type: Nephrite: Splintery. Jadeite: Granular to splintery.
• Tenacity: Extremely tough (due to interlocking crystal structure), making it resistant to breaking and chipping.
• Luster Type: Vitreous to greasy, sometimes waxy.

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