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Liliia Hryshchenko/


CCSS: 6.SP.B.4, 6.SP.B.5, 7.SP.B.3, 8.SP.A.1, MP1, MP5, MP6

TEKS: 6.12A, 6.12B, 6.12C, 6.12D, 6.13A, 7.6G, 7.12A, 8.5C, 8.11A

Diamond Discovery

For thousands of years, people have loved diamonds. The precious gems are one of the hardest materials on Earth. Rough diamonds come out of the ground looking like dull glassy rocks. But once they are cut, polished, and carved with flat sides called facets, the brilliant gems shimmer in the sunlight.  

Their rarity makes diamonds expensive. But scientists just discovered a treasure trove of the gemstones. More than 1 quadrillion tons (That’s 10^15 tons!) lie deep below Earth’s surface. That’s 1,000 times more than previously thought.

Scientists figured this out using seismic waves. Earth’s surface is constantly moving, which creates seismic waves. Scientists are constantly measuring the seismic waves. Much like X-rays that allow doctors to peer inside the human body, seismic waves reveal what lurks deep beneath Earth’s surface.

But you shouldn’t start digging for these diamonds anytime soon. “Everyone is excited because they think they might be able to get to them somehow,” says Josh Garber, a geologist at Penn State University. However, the gems are too deep for any drills to reach them.

In addition, the diamonds are trapped in a layer of molten rock called magma. In order for any of these diamonds to reach the surface, the magma would have to rush upward through a pipe of volcanic rock. 

“The types of magmas that bring diamonds up to the surface take only a couple of hours,” says Garber. “We’ve never experienced it in human history, but it would happen quickly if we did.”

Google Quiz

Click the Google Quiz button below to share an interactive version of the questions with your class. Click Download PDF for the non-interactive blank Answer Sheet.

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Jim McMahon/Mapman (maps) Boykung/ (Alexandrite); Sararwut Jaimassiri/ (Diamond); Kelly Nash/ (Serendibite); Art_girl/ (Grandidierite); Feng Yu/Alamy Stock Photo (Red Diamond)

Answer the following questions using the information in the charts and graphs above. Record your work and answers on our answer sheet.

In which country was the largest diamond discovered?

A. Brazil

B. South Africa

C. Botswana

D. Sierra Leone

How many continents had countries that were part of the Central Powers?

A. 155,400 mg

B. 162,600 mg

C. 178,000 mg

D. 222,200 mg

What percent of money spent on diamonds in 2017 was on princess-cut stones?

A. 5%

B. 8%

C. 21%

D. 29%

How many carats of grandidierite would cost the same as 1 carat of red diamond?

A. 5 carats

B. 25 carats

C. 50 carats

D. 500 carats

What was the approximate cost per carat of the highest-quality diamonds in 1980?

A. $10,500

B. $15,000

C. $21,500

D. $31,000

Between which two years in the graph was there the greatest jump in cost per carat of diamonds?

A. 1960 and 1970

B. 1970 and 1980

C. 1990 and 2000

D. 2000 and 2010

About how much more did people spend on round-cut diamonds than cushion-cut diamonds?

Of the largest diamonds discovered, what percent weighed more than 1,000 carats?

About how much more did a diamond weighing 2.4 carats cost in 2015 than in 2000?

How The Millenium Star is a high-quality diamond. How much would it have cost to buy it in the year it was discovered

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Lesson Plan (1)