Assignment 22 - Topaz & Beryl Flashcards
What are the most popular and valuable topaz varieties?
Red and pink topaz varieties, including imperial topaz, are the most rare and valuable.
Color centers and traces of chromium cause the wide variety of colors in topaz
Where does most gem-quality topaz come from?
The Ouro Preto area of Brazil is the world’s major commercial source of imperial and red topaz.
What treatments can modify the appearance of topaz?
Topaz treatments commonly involve heating or a combination of heating and irradiation.
If yellow to reddish brown topaz contains chromium, careful heat treatment can produce a pink color.
A widely used trade term for gem-quality topaz of medium reddish orange to orange-red color.
Imperial topaz
The name for imperial topaz originated in nineteenth-century Russia. At the time, the Ural Mountains were topaz’s leading source, and the pink gemstone mined there was named to honor the Russian czar. Ownership of the gem was restricted to the royal family.
A trade term for orange-to-yellow and brown topaz.
Precious topaz
Which treatment is routinely used to enhance aquamarine’s color?
Virtually all aquamarine is heat-treated to remove the yellow color component and produce a more marketable blue color.
What’s the rarest beryl variety?
Red beryl is the rarest beryl
What’s the difference between green beryl and emerald?
Tone and saturation levels distinguish green beryl from emerald.
What is aquamarine’s finest color?
The finest aquamarines are a moderately strong, medium-dark blue to slightly greenish blue.
Aquamarine generally shows its finest, most saturated color in large sizes.
Which are the major sources of aquamarine?
Brazil, Pakistan, and China are leading producers of aquamarine.
Which treatment is routinely used to enhance morganite?
Morganite is almost always heated, or irradiated first and then heated, to produce or improve the pink color.
What causes red beryl’s color?
Traces of manganese.
Which method is used to produce synthetic aquamarine?
A. Flux
B. Pulling
C. Flame fusion
D. Hydrothermal
D. Hydrothermal
Which source emerged as a leading producer of small, commercial-quality aquamarine in the 1990s?
A. China
B. Kenya
C. Colombia
D. The United States
A. China
The only source of red beryl is in the US state of
A. Utah.
B. Nevada.
C. Colorado.
D. California.
A. Utah.
