Minerals : Tigtag They are found underground... They are found in the sea... And they are even found inside your body. What are they? They are minerals. minerals There are about 3000 known minerals on Earth. A mineral is a naturally occurring solid substance that has a unique chemical makeup.mineralsolid substanceoccurs naturallyunique chemical makeup Many minerals are extremely useful. Clay is mined to make pottery. clay Precious metals, like gold, are also mined. gold Gold has many uses, from protective coatings on satellites... To jewelry. Gold is a very popular choice for jewelry because it doesn't react with moisture in the air, so it doesn't rust. And also because it is soft enough that it can be shaped into many different designs. The chemical makeup of each mineral will determine its properties and uses. The chemical makeup of a diamond makes it the hardest mineral on Earth. diamond For that reason diamond is often used on the tips of drills, as it can cut through all other substances. sodium chloride iron
The mystery of Easter Island : Tigtag Easter Island is a remote island in the Pacific Ocean. Easter Island, Pacific Ocean Hundreds of monumental stone statues, called moai, are all that remain of an ancient civilization. moai What happened to the people that built them? The Mystery of Easter Island Evidence suggests that in around 300 AD a small group of people left an island in Polynesia and travelled thousands of kilometers to the shores of Easter Island. The new arrivals settled in well and made use of the island’s natural resources. They used soil for farming, stone for building shelters, and trees for firewood and fishing boats. natural resourcessoil, stone, trees Over time the population grew dramatically. It increased from less than 100 in 300 AD to around 10,000 in 1600 AD. But then large numbers of people started to die. In the years that followed, the population had dropped drastically. When archaeologists examined bones from this time, they discovered many serious skull fractures – evidence of war! But why were they fighting?