The Heart
The heart is an incredible organ. In vertebrates, it is a hollow muscular organ that pumps...
When you think of a diamond, you probably think of jewelry. Each diamond takes quite an extensive journey before being set in a ring or necklace. Diamonds form deep underground. When certain minerals like coal are under extreme pressure and heat, diamonds can form. These conditions don't exist where people live. You have to be 90 miles under the Earth's surface. Volcanoes push diamonds up to where humans can mine them. The deepest diamond mine in the world is about two miles deep. When they come out of the ground, diamonds are dull, yellow lumps. Only a small number of them can become the brilliant gems in jewelry stores. These jewelry-quality stones are sorted from the others. Next expert cutters carefully shape the stone from a lump into a sparkly jewel. Finally jewelers place the diamonds into rings or bracelets or earrings. When you see a diamond glinting on someone's finger, it is hard to believe it started out 90 miles underground!
The heart is an incredible organ. In vertebrates, it is a hollow muscular organ that pumps...
Clouds are named according to three main features. The first feature is the shape of the c...
The North Pole, also called True North, is the northernmost point on Earth. When you are s...