Shell Pearl Gem Guide and Properties Chart

“Shell pearls” are imitation pearls. A mother of pearl bead nucleus is coated to resemble Tahitian, South Sea, or freshwater cultured pearls. They are an affordable alternative to their more expensive counterparts.

General Information

Classification
Optical Properties
Characteristic Physical Properties
Chemistry & Crystallography

Common Name

Shell Pearl

Species

Shell

Transparency

Translucent - Opaque

Dispersion

Strength: None

Refractive Index

1.530-1.685

Polariscope Reaction

Aggregate (AGG)

Fluorescence

SWUV: Variable
LWUV: Variable

CCF Reaction

None

Pleochroism

None

Streak

White

Specific Gravity

2.700-2.890

Toughness

Fair

Inclusions

Shells might show orient and will have a parallel growth structure. Shell pearls will often have a flame-like structure. Numerous minute particles that create a sparkle effect. Lack of overlapping aragonite platelets under magnification. Chips in coating.

Luster

Greasy, Pearly

Fracture

Uneven, Splintery

Cleavage

None

Chemical Name

Calcium carbonate+conchiolin+water

Chemical Formula

CaCO₃+conchiolin+H₂O

Crystal System

Chemistry Classification

Organic

Shell Pearl Colors

Bi-color
Black
Blue
Brown
Gray
Green
Multi-color
Multi-color
Orange
Pink
Purple
Red
White
Yellow

Alternate Names

Imitation Pearl, Pearl Simulant, "South Ocean pearl", South Pacific pearl", "Oustah de Luxe" pearl, "Composite pearls", "Micomo pearls", "Masami"

Countries of Origin

Unknown; China; Indonesia

History

Mother of Pearl nucleus are often used to simulate pearls. The Tridanca gigas has a white shell and are frequently used in the manufacture of "Shell pearls".

Care

Soluble in hydrochloric acid