How to identify K2 Jasper

To correctly identify K2 Jasper (Granite with Azurite inclusions), 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

   White to off-white granitic matrix with distinct, often spherical, bright blue azurite inclusions. Minor green malachite may also be present.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Granitic matrix is typically vitreous to dull; azurite inclusions are dull to earthy.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Fine-grained to medium-grained phaneritic texture for the granite. Azurite inclusions are typically cryptocrystalline to microcrystalline.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Granite consists of interlocking anhedral to subhedral crystals of quartz, feldspar, and mica. Azurite inclusions are typically massive, nodular, or botryoidal within the granite.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   Granite components (feldspar, mica) exhibit cleavage; quartz has no cleavage. Azurite has perfect cleavage in one direction, but is rarely observed in massive form.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Intrusive igneous bodies (granite batholiths or stocks) that have subsequently undergone hydrothermal alteration, allowing for the precipitation of copper minerals like azurite within the existing rock.

Key Facts

Hardness

Granite matrix: 6-7 (Mohs); Azurite inclusions: 3.5-4 (Mohs)

Specific Gravity

Granite matrix: 2.6-2.7 g/cm³; Azurite: 3.77-3.89 g/cm³ (overall rock will be intermediate)

Crystal System

Granite: Polycrystalline aggregate (Quartz: Trigonal, Feldspar: Monoclinic/Triclinic, Mica: Monoclinic); Azurite: Monoclinic

Color

White to off-white with bright blue spots (azurite) and sometimes green (malachite)

Luster

Vitreous to dull (granite), dull to earthy (azurite)

Transparency

Opaque

Fracture

Granite: Uneven to conchoidal; Azurite: Conchoidal

Cleavage

Granite: Feldspar has good cleavage, mica has perfect basal cleavage, quartz has none; Azurite: Perfect in one direction, good in another

Composition

Granite (Quartz, Feldspar, Mica) with Azurite (Cu3(CO3)2(OH)2) and minor Malachite (Cu2(CO3)(OH)2)

Physical characteristics

• Crystal Habit: Granite: Granular, massive; Azurite: Massive, nodular, botryoidal within the granite matrix.
• Cleavage Type: Granite: Feldspar (2 directions at ~90°), Mica (1 perfect basal); Azurite: Perfect {021}, good {100}.
• Fracture Type: Granite: Uneven to subconchoidal; Azurite: Conchoidal.
• Tenacity: Granite: Brittle; Azurite: Brittle.
• Luster Type: Granite: Vitreous to dull; Azurite: Dull to earthy.

Explore K2 Jasper