Ultimate Rock Quiz
Rocks are all over the place -- you probably don't give 99 percent of them a thought as you go about your day. But there are obviously many types of rock -- from the gravel under your feet to towering sandstone formations to massive diamonds.
Question 2 of 11
What are the three basic types of rock found on Earth?
... Igneous, sedimentary and metamorphic are the big three. Each classification has many subcategories.
Question 3 of 11
How is igneous rock formed?
... Igneous rock is made from molten magma that has cooled and solidified over time. It makes up about 95 percent of the Earth's crust.
Question 4 of 11
What kind of rock covers the seafloor?
... Basalt, the most common volcanic rock, forms the ocean floor.
Question 5 of 11
Pressure and temperature conditions take igneous and sedimentary rocks and transform them into metamorphic rocks. In this way, limestone turns into what kind of metamorphic rock?
... Limestone is a sedimentary rock that -- when it's heated and squeezed in the right conditions -- transforms into marble.
Question 6 of 11
What's the difference between stalactites and stalagmites?
... Ah, that age-old question. Stalactites are rock formations that drop from the ceiling of a cave and stalagmites grow from the floor.
Question 7 of 11
What is the study of caves called?
... The scientific study of caves is called speleology -- and the exploration of caves for fun is spelunking.
Question 8 of 11
El Capitan, the famous rock formation in Yosemite National Park, is made of what kind of rock?
... Rock climbers from the world over journey to Yosemite to scale El Capitan's vertical granite face.
Question 9 of 11
How many sandstone arches are contained within Arches National Park in Utah?
... There are about 2,000 arches in the park, the most famous of which is Delicate Arch.
Question 10 of 11
What are the "four Cs" of diamonds?
... When you're shopping for a diamond, you'll want to remember the four Cs: cut, clarity, carat and color.
Question 11 of 11
How many carats was the largest diamond ever found?
... The Cullinan diamond, unearthed in 1905 from a mine in South Africa, was 3,106 carats.
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