Tortoise Shell | Gemopedia

Tortoise shell used in ornamentation traditionally comes from the shell of the hawksbill sea turtle. The multicolored marbled patterns of the shell are coveted not only for their unique colorations, but also their deep translucence. When heated, the shell becomes soft and can be molded into jewelry and other decorated articles. Due to the depletion of the species today, its use is illegal in many countries and has primarily been replaced by synthetic tortoise shell.
Colors
Mottled Yellow, Brown, Sometimes Black, White

Tortoise Shell Classification

Common Name

Tortoise Shell

Species

NA

Variety

Colors

Mottled Yellow, Brown, Sometimes Black, White

Alternate Names

Gemstone Groups

Key Separations

Appearance, RI and magnification. Will smell like burning hair during hot point test.

Comments

Hawksbill turtles are an endangered species and importation of tortoise shell is against U.S. law. It is also a protected species under the CITES agreement.

Tortoise Shell Optical Properties

Transparency

Semitransparent - Semitranslucent

Refractive Index

1.55-1.644
Tolerance:(-0.010)

Birefringence

Optic Character

NA

Optic Sign

NA

Polariscope Reaction

Singly Refractive (SR)

Fluorescence

SWUV: Inert to moderate bluish white
LWUV: Inert to moderate bluish white

CCF Reaction

Pleochroism

None

Dispersion

Comments

Tortoise Shell Chemistry & Crystallography

Chemical Name

keratin

Chemical Formula

Synthesis

Crystal System

NA

Classification

Organic

Nature

Natural

Crystallinity

Amorphous

Comments

Tortoise Shell Characteristic Physical Properties

Hardness

2.5

Streak

Specific Gravity

1.26-1.35 Typical:1.29

Toughness

Fair

Inclusions

Tortoise shell will have mottled coloration, numerous spherical particles that give it a dot like pattern under magnification. Plastic imitations will have a swirl like pattern.

Luster

Waxy

Stability

Fracture

Uneven, Splintery

Cleavage

None

Comments

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