How to identify Unakite, Chrysocolla

To correctly identify Unakite, Chrysocolla (Unakite (Epidote-Feldspar rock), Chrysocolla), 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

   Unakite: Mottled pink (orthoclase), green (epidote), and sometimes clear/gray (quartz). Chrysocolla: Blue, blue-green, green, often with brown or black inclusions.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Unakite: Vitreous to greasy (feldspar, quartz), vitreous (epidote). Chrysocolla: Vitreous to dull, sometimes waxy or earthy.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Unakite: Granular, medium to coarse-grained. Chrysocolla: Massive, botryoidal, reniform, stalactitic, or encrusting.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Unakite: Anhedral to subhedral grains of constituent minerals. Chrysocolla: Typically cryptocrystalline to amorphous; rarely forms small prismatic crystals.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   Unakite: Orthoclase has two distinct cleavages at 90 degrees; epidote has one perfect cleavage. Chrysocolla: None, due to its cryptocrystalline nature.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Unakite: Metamorphic terrains, particularly where granitic rocks have undergone metasomatism or regional metamorphism. Chrysocolla: Oxidation zones of copper sulfide deposits, often associated with malachite, azurite, cuprite, and native copper.

Key Facts

Hardness

Unakite: 6-7 (Mohs, composite of constituent minerals). Chrysocolla: 2.5-3.5 (Mohs).

Specific Gravity

Unakite: 2.8-3.2 (composite). Chrysocolla: 2.0-2.4.

Crystal System

Unakite: Monoclinic (epidote), Triclinic (feldspar), Hexagonal (quartz). Chrysocolla: Orthorhombic (rarely), typically amorphous or cryptocrystalline.

Color

Unakite: Pink, green, clear/gray. Chrysocolla: Blue, blue-green, green.

Luster

Unakite: Vitreous to greasy. Chrysocolla: Vitreous to dull, waxy, earthy.

Transparency

Unakite: Opaque to translucent. Chrysocolla: Translucent to opaque.

Fracture

Unakite: Uneven to conchoidal (quartz), splintery (epidote). Chrysocolla: Conchoidal to uneven.

Cleavage

Unakite: Orthoclase (2 directions at 90°), Epidote (1 perfect). Chrysocolla: None.

Composition

Unakite: Orthoclase feldspar (KAlSi3O8), Epidote (Ca2(Al,Fe)3(SiO4)3(OH)), Quartz (SiO2). Chrysocolla: (Cu,Al)2H2Si2O5(OH)4·nH2O (hydrous copper phyllosilicate).

Physical characteristics

• Crystal Habit: Unakite: Granular aggregate. Chrysocolla: Massive, botryoidal, reniform, stalactitic, encrusting.
• Cleavage Type: Unakite: Good in orthoclase, perfect in epidote. Chrysocolla: Absent.
• Fracture Type: Unakite: Uneven to conchoidal. Chrysocolla: Conchoidal to uneven.
• Tenacity: Unakite: Brittle. Chrysocolla: Brittle.
• Luster Type: Unakite: Vitreous to greasy. Chrysocolla: Vitreous to dull, waxy, earthy.

Explore Unakite, Chrysocolla