Scallop Pearls | Gemopedia

A non-nacreous calcareous concretion, scallop pearls may form in any member of the scallop family. A very rare occurrence, such pearls are typically collected by fishermen as a result of harvesting the meat of the shellfish. They are found in the coastal waters of Central and North America, especially Baja California. Unlike other calcareous concretions, scallop pearls are a maroon to plum color and often form in oval, drop-like shapes.
Alternate
Names
Lion's Paw Pearl, Digby Scallop Pearls
Colors
Brown, Tan, Purple, Yellow, Orange Interior Color White, Root Beer Color

Scallop Pearls Classification

Common Name

Scallop Pearls

Species

Pearl

Variety

Colors

Brown, Tan, Purple, Yellow, Orange Interior Color White, Root Beer Color

Alternate Names

Lion's Paw Pearl, Digby Scallop Pearls

Gemstone Groups

Key Separations

Appearance, RI, birefringence blink and magnification. A "tooth test" is commonly used in which a pearl is rubbed against a tooth; if gritty, this is an indication that the surface is nacre, versus plastic and glass imitations that feel smooth.

Comments

Lion's paw pearls are produced by the lion's paw scallop Nodipecten subnodosus and can originate from the coast of Central America, Baja California and the inland Sea of Cortx in Mexico. Atlantic Sea Scallop (Placpecten magellanicus) produces the scallop pearls that come from Digby, Nova Scotia.Atlantic sea scallops are produced by the North Atlantic deep-sea scallop, Placopecten magellanicus; the Atlantic bay scallop, Argopecten irradians, and the Atlantic Lion's Paw, Nodipecten nodosus.

Scallop Pearls Optical Properties

Transparency

Translucent - Opaque

Refractive Index

1.53-1.685

Birefringence

0.155

Optic Character

NA

Optic Sign

NA

Polariscope Reaction

Aggregate (AGG)

Fluorescence

SWUV:
LWUV:

CCF Reaction

Pleochroism

None

Dispersion

Comments

Scallop Pearls Chemistry & Crystallography

Chemical Name

calcium carbonate + conchiolin and water

Chemical Formula

CaCO3

Synthesis

Crystal System

NA

Classification

Organic

Nature

Natural

Crystallinity

Aggregate

Comments

Scallop Pearls Characteristic Physical Properties

Hardness

2.5-4.5

Streak

Specific Gravity

2.61-2.85

Toughness

Good

Inclusions

Lion's paw pearls sometimes have platelets that display adventuresence. They have a fibrous structure that has a patchwork like appearance. Lion's paw pearls are brown, purple, yellow and orange with an interior color of white, purple or root beer colorDigby scallop pearls are white or pale tan in color and have a silvery sheen. The appearance has roughly circular patches with a radiating pattern caused by parallel calcite fibers.

Luster

Dull

Stability

Poor

Fracture

Uneven

Cleavage

None

Comments

JTV on Google+
0 Items
My Wish List
Close
Item
Description
Qty.
Price


Estimated Order Total:
0
Total Due Today:
0
Close
Item
Description
Qty.
Price


Page of 1