Assignment 27 - Organics and Collectors’Stones Flashcards
What are the ancient origins of many organic gems?
Archeologists have found amber artifacts dating as far back as 10,000 BC.
Coral’s earliest known use in jewelry dates back 30,000 years. Besides using coral ornamentally, ancient peoples attributed magical powers to it. Among other benefits, coral was thought to protect its wearer from death.
The earliest known decorative use of ivory is a small head carved from mammoth ivory about 30,000 years ago.
Why is it necessary to protect some organic gem sources?
Over-harvesting and pollution have almost wiped out red coral along the sea’s African and European coasts
How are organic gems used in jewelry?
Artisans fashion calcareous coral into beads, cabochons, carvings, and cameos.
You’ll see ivory in jewelry as carvings, cabochons, beads, and bangle bracelets. Artisans shape ivory with saws, drills, and lathes. Like wood- workers, they use chisels to carve ivory, and finish it by burnishing and polishing the surface to a high luster.
Circular marks sometimes left in amber when treaters heat and oil it.
Sun spangles
What is a collectors’ gem?
A gem that is rare and not well known to consumers.
What has led many collectors’ gems to become more commonly used in
jewelry?
Television marketing
How is the presence of collectors’ gems increasing in the mainstream gem market?
Television marketing
Tortoise shell is composed of
A. resin.
B. protein.
C. calcium.
D. aragonite.
B. protein.
Jet is an ornamental form of
A. resin.
B. calcium.
C. conchiolin.
D. lignite coal.
D. lignite coal.
Which of the following gems is a natural glass?
A. Sphene
B. Kyanite
C. Fluorite
D. Moldavite
D. Moldavite
What’s coral’s most attractive color?
The most valuable red coral is an intense red that dealers call oxblood.
What is the most important coral marketing center?
Italy.
Because Italy is the most important coral-marketing center, many coral color terms are Italian.
The major source of jet is
A. England.
B. Australia.
C. South Africa.
D. the United States.
A. England.
The only source of gem-quality benitoite is
A. Mogok.
B. Ratnapura.
C. California.
D. the Umba River Valley.
C. California.
Which of the following is a calcium carbonate?
A. Jet
B. Amber
C. Pink coral
D. Golden coral
C. Pink coral