Global Gemology - Rare Gems & Jewels
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TORTOISE SHELL

Picture
Victorian era antique hair pin with tortoise shell and solid gold, by T.B. Starr of Black, Starr & Frost
Photo courtesy of Scott Papper, GIA GG, AJP, CMA (NAJA), Global Gemology & Appraisals
Species:  Tortoise Shell
​​Mohs Hardness:  3 out of 10
Color:  Semi-transparent to semi-translucent, mottled yellow and brown
RI:  1.550 (-0.010)
Birefringence:  None
SR/DR/AGG:  SR
Fluorescence:  Colorless and yellow portions show bluish white under LW and SW
SG:  1.29 (+0.06 / -0.03)

Tortoise Shell Facts

Picture
Cartier designer eyeglasses with tortoise shell frames
Photo courtesy of Frank Papper, Deerfield Pawnbrokers

Tortoise shell that is used in jewelry is usually derived from the shell of the hawksbill sea turtle.

​It has a translucent, mottled pattern, and can be molded when heated.
  • HOME
  • ABOUT
  • SHOP
  • SERVICES
    • APPRAISALS
    • EXPERT WITNESS TESTIMONY
    • SELL YOUR JEWELRY
  • GEMOLOGY
    • GEM ENCYCLOPEDIA
    • THE ART OF GEMOLOGY
  • JEWELRY EDUCATION
    • DIAMOND FACTS
    • JEWELER DIRECTORY
    • JEWELRY PERIODS
    • POCKET WATCHES
    • NATIVE AMERICAN JEWELRY
  • GLOSSARY