What is a mineral? -- How do people use minerals? -- What is a rock? -- What is an igneous rock? -- What are some kinds of igneous rocks? -- Do all igneous rocks contain mineral crystals? -- Where on Earth are igneous rocks? -- Where else are igneous rocks found? -- How do people use igneous rocks? -- What is a sedimentary rock? -- What are some kinds of sedimentary rocks? -- How can you identify sedimentary rocks? -- Where on Earth are sedimentary rocks? -- How do people use sedimentary rocks? -- What is a metamorphic rock? -- What are some kinds of metamorphic rocks? -- How can you identify metamorphic rocks? -- Where on Earth are metamorphic rocks? -- How do people use metamorphic rocks? -- How are rocks recycled? -- What is an ore? -- What is a gemstone? -- Where on Earth are gemstones? -- Meet the geologist.