Shell
Consumer Information
What color is it?: Virtually every color in the rainbow.
What is the story behind this gemstone?: Shells are the oldest form of jewelry...and money for that manner. Shells decorations have been found as jewelry in the oldest known burial grounds. Today there are a number of types of shells still being used as ornamental jewelry. Most common is the mother of pearl shell material taken from the inner lining of oyster shells as shown above and below.
Can I wear it everyday?: Well....sure why not. Unless you have something very rare there is a fairly good supply of almost every kind of shell used in jewelry.
Is it expensive?: Generally no. But there are always exceptions.
Is it a birthstone?: No.
What do I need to know before
going shopping?: Nothing.
Shells are used from everything from the inexpensive puka
necklaces of the 1970's, to mother of pearl inlays
on fairly expensive jewelry used today. But since there is very
little use of imitations, other than plastic which is fairly easy
to identify, there is just not much to worry about with shell
jewelry.
General
Information
Abalone shell buttons shown above.
Source: World Wide
Chemical: CaCo3 (calcium carbonate or aragonite just like pearls and what else......TUMS)
Formation: Well.....as shells for sea creatures.
Crystal System: None
Unusual Properties: Several including orient and play of color (well....sort of)
Gemological Information
Mother-of-pearl from the inside lining of an oyster shell shown above and at top.
RI: 1.52 - 1.56 varies the same of pearls
Birefringence: .014 but again varies
Optic Character: None
Specific Gravity: 2.60 - 2.78 + -
Hardness: 3 - 4
Transparency: Translucent to Opaque
Special Identifying Properties and Tests: Gritty to the teeth test, separated from plastic by flow lines and concave surfaces of plastic.
Synthetics: None.
Imitations: Many possible with plastics