How to identify Ocean Jasper

To correctly identify Ocean Jasper (Orbicular Jasper (a variety of Chalcedony, SiO2)), 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

   Extremely variable, including shades of green, yellow, pink, red, white, cream, grey, and brown. Often multi-colored within a single specimen.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Vitreous to waxy, dull in unpolished specimens.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Smooth and dense when polished; rough to slightly granular in its natural state. Characterized by distinct orbicular patterns.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Cryptocrystalline (microscopic crystals), forming botryoidal or mammillary masses within cavities, often with concentric banding.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   None (due to its cryptocrystalline nature).

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   Hydrothermal veins and amygdaloidal cavities within rhyolitic volcanic flows, typically found near coastal areas.

Key Facts

Hardness

6.5-7 on the Mohs scale

Specific Gravity

2.58-2.64

Crystal System

Trigonal (cryptocrystalline aggregates)

Color

Highly variable: green, yellow, pink, red, white, grey, brown, often multi-colored with orbicular patterns

Luster

Vitreous to waxy

Transparency

Opaque to translucent

Fracture

Conchoidal to splintery

Cleavage

None

Composition

Silicon dioxide (SiO2) with various mineral inclusions

Physical characteristics

• Crystal Habit: Cryptocrystalline aggregates, forming botryoidal, mammillary, or nodular masses with concentric banding (orbicular structures).
• Cleavage Type: None
• Fracture Type: Conchoidal to splintery
• Tenacity: Brittle
• Luster Type: Vitreous to waxy

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