How to identify Turquoise

To correctly identify Turquoise (Turquoise), 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

   Ranges from sky-blue to greenish-blue, apple-green, and yellowish-green. The most valued color is an intense, uniform sky-blue.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Waxy to subvitreous, dull in massive forms.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Typically massive, cryptocrystalline, or reniform (kidney-shaped). Can be found as veinlets or crusts. Often has a fine-grained, porcelain-like texture.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Rarely forms distinct crystals; when it does, they are small, triclinic prisms. Usually found as cryptocrystalline aggregates, nodules, or encrustations.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   Perfect on {001} and good on {010}, but rarely observed due to its cryptocrystalline nature. Fracture is typically conchoidal to uneven.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Found in arid regions, typically in weathered zones of aluminum-rich igneous or sedimentary rocks that contain secondary copper mineralization. It forms in veins, nodules, and concretions within limonite, sandstone, or altered volcanic rocks.

Key Facts

Hardness

5-6 (Mohs scale)

Specific Gravity

2.60-2.90

Crystal System

Triclinic

Color

Blue, greenish-blue, green

Luster

Waxy, subvitreous, dull

Transparency

Opaque

Fracture

Conchoidal to uneven

Cleavage

Perfect on {001}, good on {010} (rarely observed)

Composition

Hydrous copper aluminum phosphate

Physical characteristics

• Crystal Habit: Cryptocrystalline masses, nodules, reniform, botryoidal, stalactitic, veinlets, encrustations. Rarely as small, tabular triclinic crystals.
• Cleavage Type: Perfect on {001}, good on {010}. Due to its cryptocrystalline nature, cleavage is seldom seen in hand specimens.
• Fracture Type: Conchoidal to uneven, splintery.
• Tenacity: Brittle
• Luster Type: Waxy to subvitreous, dull in massive forms.

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