How to identify Faceted Gemstone

To correctly identify Faceted Gemstone (Mineral (specific type not identifiable from image)), 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

   Highly variable, depending on the specific mineral. Can be colorless, or any color of the spectrum.

2. 2

   Luster

   How the surface reflects light: metallic, vitreous, dull

   Typically vitreous (glassy) to adamantine (diamond-like) due to polishing, but can vary based on the mineral's inherent luster.

3. 3

   Texture

   Grain size and surface feel: coarse, fine, glassy

   Smooth and polished on the faceted surfaces; sharp edges between facets.

4. 4

   Crystal Form

   Shape of visible crystals or crystal faces

   Not applicable to the faceted form, as it is an artificial shape. The original mineral would have a specific crystal habit.

5. 5

   Cleavage

   How it breaks: flat cleavage planes vs irregular fracture

   Not directly observable in a finished faceted gem without destructive testing. The presence and quality of cleavage are inherent to the original mineral.

6. 6

   Geological Environment

   The rock formation and setting where it occurs

   The original mineral forms in diverse geological environments, including igneous intrusions (e.g., pegmatites for beryl, topaz), metamorphic rocks (e.g., schists for garnet, ruby), and alluvial deposits (secondary concentration of durable gems).

Key Facts

Hardness

Varies widely (e.g., Diamond 10, Corundum 9, Quartz 7 on Mohs scale).

Specific Gravity

Varies widely (e.g., Diamond 3.52, Corundum 4.00, Quartz 2.65).

Crystal System

Varies widely, depending on the specific mineral (e.g., isometric, hexagonal, orthorhombic).

Color

Highly variable, depends on the specific mineral.

Luster

Vitreous to adamantine.

Transparency

Typically transparent to translucent, as opaque minerals are rarely faceted for brilliance.

Fracture

Varies widely (e.g., conchoidal, uneven, splintery), depends on the specific mineral.

Cleavage

Varies widely (e.g., perfect, good, poor, none), depends on the specific mineral.

Composition

Varies widely, depends on the specific mineral (e.g., C for diamond, Al2O3 for corundum, SiO2 for quartz).

Physical characteristics

• Crystal Habit: Not applicable to the faceted form; refers to the natural growth shape of the mineral.
• Cleavage Type: Varies depending on the specific mineral (e.g., octahedral for diamond, basal for topaz).
• Fracture Type: Varies depending on the specific mineral (e.g., conchoidal for quartz, uneven for garnet).
• Tenacity: Varies depending on the specific mineral (e.g., brittle, tough).
• Luster Type: Vitreous to adamantine (due to polishing), but can be sub-vitreous or resinous for some minerals.

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