SHELL

Beautiful shell cameo hand-carved by a master carver

Species:  Shell
Mohs Hardness: 3 out of 10
Color: Wide range of colors, and can be multi-colored due to banded layers. Can also have phenomena such as iridescence.
RI: 1.530 to 1.685
Birefringence:  0.155 (birefringence blink)
SR/DR/AGG: AGG
Optic Character:  Uniaxial positive
Spectrum: Not diagnostic
Fluorescence: Varies
SG: 2.86 (+0.03 / -0.16)

Shell Types

CARNELIAN SHELL

Hand carved carnelian shell cameo habillé

The carnelian shell is the most common shell used for cameo carvings.

Most carnelian shells are found off of West Africa. They grow rather rapidly and are harvested on a regular basis.

Carnelian shells range in color from reddish-brown, to peach, to orange.

The raised layer isn't completely white, and will usually include a bit of a peach tinge.

SARDONYX SHELL

Hand carved sardonyx shell brooch

Sardonyx shells grow at a much slower rate than carnelian shells. Much fewer sardonyx shell cameos are produced each year, making them more rare.

Sardonyx shell cameos have a raised white layer atop a deep red or dark chocolate brown background, and are generally more desirable due to their contrasting layers of color.

QUEEN CONCH SHELL

Art Nouveau Era queen conch shell cameo brooch

Most queen conch shells are found off the coast of the Bahamas. Queen conch shell cameos are white with subtle pink coloring.

Conch cameos are often mistaken for angelskin coral cameos.

MOTHER OF PEARL SHELL

Mother of pearl, diamond and jet inlay in a sterling silver cuff bracelet.

Cuff bracelet with mother of pearl and jet inlay

Pearl mollusks and mussels produce a hard, protective coating inside their shell. These layers of nacre have a rainbow-colored, iridescent sheen, and are known as mother of pearl.

Mother of pearl has a white to light grey bodycolor, with an iridescent, "oil slick" flash.

ABALONE SHELL

Abalone mother of pearl shell channel inlay in a sterling silver feather brooch

Colorful abalone shell inlay brooch

Abalone are small to very large sea snails found along the coasts of every continent with the exception of South America's Pacific coast.

Abalone shells produce iridescent layers of nacre along the inside of the shell. These iridescent layers are known as "mother of pearl".

Abalone mother of pearl is known for its dark bodycolor with a rainbow-colored, iridescent flash.

SPINY OYSTER SHELL

Navajo spiny oyster shell ring

Spiny oyster shells are vibrantly colored, and can be red, orange, pink or purple.

Spiny oysters, also known as spondylus, aren't actual oysters, but a family of mollusks.

Spiny oyster shell is commonly used in Southwestern jewelry.

TIGER SHELL

Hand carved tiger shell Venetian cameo

Tiger shells come from large sea snails, known as cypraea tigris. These snails are found on the ocean floor, near coral habitats, off the coasts in the Indo-Pacific region.

Their shells have a wild, spotted appearance, resembling the fur of a tiger or leopard.

Tiger shells have up to 7 different layers of color: brown on the surface, then white-yellowish, grey-blue, 2 tones of purple, and then finally a bluish-white.