Sedimentary rocks: Limestone cliffs in Saudi Arabia Before sedimentary rocks When the Earth was first forming, about six billion years ago, there weren't any sedimentary or metamorphic rocks. The only [...]
Erosion of a cliff in Canada Igneous rocks came first When the Earth first formed, about four and a half billion years ago, it was all liquid rock and liquid [...]
What is quartz? A chunk of white quartz What is quartz made of? Quartz is an igneous rock made out of molecules of silicon and oxygen atoms held together in [...]
History of tomatoes: Wild tomatoes Wild tomatoes in the Andes The earliest tomatoes were little sour berries. They grew on low bushes in dry, sunny places in the Andes mountains [...]
Soil types triangle What is dirt made of? All dirt is basically made of three different kinds of particles, as Aristotle and his student Theophrastus saw in the 300s BC. [...]
Pyramid project: building a sand pyramid A pyramid project Ancient Egyptian pharaohs, like Mayan lords, built pyramids because they're a pretty easy shape to build. Pyramids are especially easy to [...]
Diagram of a silicon atom When a red giant star is getting older and runs out of helium fuel, it starts to convert the oxygen atoms in the star into silicon [...]
Sand castle by the ocean If you want to see some real silica, go to the beach or to a playground with a sandbox. Beach sand (which is also what [...]
Sandboxes can carry roundworms Roundworms are a serious health problem today in North America, especially in warm places where the cold doesn't kill them in the winter. Roundworms make kids tired, [...]
