Quahog Pearl
Pearl
Published: June 2014
Modified: September 2023
Among America's rarest and most stunning pearls, quahog pearls were first valued by Native Americans along the coast of New England. This non-nacreous calcareous concretion forms in colors from white to brown, to purple and lilac in round, button and teardrop shapes. Such pearls are typically collected by fishermen as a result of harvesting the meat of the shellfish.
General Information
Common Name
Quahog Pearl
Species
Pearl
Transparency
Translucent - Opaque
Refractive Index
1.530-1.685
Birefringence
0.155
Optic Character
NA
Optic Sign
NA
Polariscope Reaction
Aggregate (AGG)
Pleochroism
None
Hardness
2.5-4.5
Specific Gravity
2.610-2.850
Toughness
Good
Inclusions
Quahog pearls are non-nacreous with fibrous structure. They have a color banding that sometimes creates an "eye" effect.
Luster
Dull, Vitreous
Stability
Poor
Fracture
Uneven
Cleavage
None
Chemical Name
calcium carbonate + conchiolin and water
Chemical Formula
CaCO3 with H2O and other organic materials
Crystal System
NA
Chemistry Classification
Organic
Quahog Pearl Colors
-
Black -
Brown -
Purple -
White -
Yellow
Alternate Names
Cohog And Quohog
Countries of Origin
Unknown; United States of America
Care
Avoid cosmetics, perfumes, hairsprays, heat and household chemicals.
Species/Variety
Quahog Shell
Quahog shell exhibits attractive bands when polished. Native Americans polished them into beads called wampum.
Quahog Shell Quahog Pearl
Common Name
Quahog Shell
Stability
Poor