By Neal Lineback and Mandy Lineback Gritzner, Geography in the NewsTM & Maps.com
AQUAMARINE AND DIAMONDS
A new gem at the Smithsonian National Museum of Natural History is upstaging what is likely the world’s most popular gem exhibit—the Hope Diamond. The Dom Pedro Aquamarine, at 10,363 carats (2.1 kg), is the largest cut and polished aquamarine gem in the world. By comparison, the Hope Diamond has 45.52 carats (0.009 kg).
While the Dom Pedro is huge and visually exquisite, in terms of monetary value per carat, diamonds reign as the most valuable gems in the world.
According to the Mineral & Gemstone Kingdom website, aquamarine crystals are a greenish-blue to blue variety of beryl that can be quite large and totally transparent. Aquamarine can form in stunningly flawless crystals, creating beautiful mineral masterpieces. The Dom Pedro, discovered in Brazil, is the largest ever found. The cut gem measures seven inches (18 cm) tall and four inches (10 cm) wide at its base.
Huge, high quality aquamarine gems can bring premium prices in the millions of dollars. In the case of the Dom, it was purchased by wife and husband Jane Mitchell and Jeffrey Bland, who donated it to the Smithsonian Museum in Washington, D.C.
Aquamarine is relatively abundant and is widely dispersed around the globe. High quality gems are found in fairly concentrated areas, however. Northern Pakistan has the reputation for the best aquamarine gems, but is followed by the Brazilian Highlands, China’s Sichuan Province, Russia’s Urals, Northern Myanmar (Burma), Nigeria’s Jos Plateau, Madagascar and Namibia. Five U.S. states also are known for gem quality aquamarine: Colorado, Idaho, California, Connecticut and Massachusetts.
Among all of the valuable gems, however, it is the diamond that has achieved international status through its association with marriage customs, particularly in the West, and its relative scarcity and beauty. Only about 20 percent of the world’s diamonds are of gem quality. The remaining 80 percent, revered for the stones’ hardness and heat conductivity, are used as industrial diamonds in tooling, drilling and cutting other hard materials.
Because the precise conditions creating diamonds occur so infrequently, major concentrations of gem-quality diamonds are found in only a few regions: central and southern Africa, India, Siberia, Canada and northeast Brazil, most notably.
Since the 1870s, most gem-quality diamonds have been mined in Africa. About 65 percent of the world’s diamonds originate from central and southern Africa, while 20 percent come from Siberia. For 2010, Botswana was the world’s leading diamond producer with 25 million carats (5,000 kg) of diamonds. Russia (mostly the Siberian region) came in second with 17.8 million carats (3,560 kg), followed by Angola (12.5 million carats/2,500 kg), Canada (11.8 million carats/2,360 kg) and Democratic Republic of Congo (5.5 million carats/1,100 kg).
Many times, very valuable resources, particularly in developing countries, enter illicit international trade. For example, diamonds (and elephant ivory) allegedly are funding guerrilla wars across Central Africa. Aquamarine, however, has not had that reputation, in part, because there are so many source areas and because the gems are not so well known among the general public. Nonetheless, they are beautiful gems.
The Dom Pedro gem is truly an amazing spectacle and the Smithsonian is experiencing international interest because of its gargantuan size and beauty. Although the Hope Diamond remains the top of gems in value, the Dom Pedro aquamarine has a beauty and brilliance all its own.
And that is Geography in the NewsTM. .
Co-authors are Neal Lineback, Appalachian State University Professor Emeritus of Geography, and Geographer Mandy Lineback Gritzner. University News Director Jane Nicholson serves as technical editor.
Sources: GITN #635, “Diamonds in the Rough,” Aug. 2, 2002; http://www.voanews.com/content/new-gem-upstages-smithsonians-hope-diamond-dom-pedro-aquamarine/1560747.html ; http://www.minerals.net/mineral/aquamarine.aspx; and http://geology.com/articles/gem-diamond-map/
This is abbreviated version of GITN 1179 Aquamarine and Diamonds. Nearly 900 of the 1200, full-length weekly Geography in the News articles are available in the K-12 online education resource Maps101, including maps and other supporting materials and critical thinking questions.