How to identify Nephrite Jade

To correctly identify Nephrite Jade (Nephrite), 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

   Typically green (light to dark, often mottled), but also white, cream, yellow, brown, grey, and black. Color is often uniform or subtly banded/mottled.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Greasy to vitreous, sometimes waxy.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Smooth, dense, and often translucent to opaque. The microcrystalline, interlocking fibrous texture is key to its toughness.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Massive, compact, and fibrous aggregates. Individual crystals are microscopic and not visible to the naked eye.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   No distinct cleavage due to its interlocking fibrous nature, but exhibits a splintery or fibrous fracture.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Found in serpentinized ultramafic rocks (e.g., peridotite, dunite) and in contact metamorphic zones of dolomitic limestones, often associated with fault zones or regional metamorphic belts.

Key Facts

Hardness

6-6.5 on the Mohs scale

Specific Gravity

2.90-3.03

Crystal System

Monoclinic (as individual tremolite-actinolite crystals, but massive aggregate)

Color

Green (various shades), white, cream, yellow, brown, grey, black

Luster

Greasy to vitreous, waxy

Transparency

Translucent to opaque

Fracture

Splintery, fibrous, conchoidal (rarely)

Cleavage

None observed in massive form due to interlocking fibers; individual tremolite-actinolite crystals have perfect prismatic cleavage at 56 and 124 degrees.

Composition

Calcium magnesium iron silicate hydroxide

Physical characteristics

• Crystal Habit: Massive, compact, interlocking fibrous aggregates (felted texture)
• Cleavage Type: Not observable in massive form; individual tremolite-actinolite crystals exhibit perfect prismatic cleavage {110}
• Fracture Type: Splintery, fibrous, occasionally conchoidal
• Tenacity: Extremely tough (resistant to breaking and chipping)
• Luster Type: Greasy to vitreous, sometimes waxy

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