6. Quartz- Quartz has been known since pre-historic times. Quartz is the most common mineral found on the surface of the earth. It's found on many types of igneous, metamorphic, and sedimentary rocks. This natural form of silicon dioxide is found in a wide range of colors and varieties. http://www.mindat.org/min-3337.html
7. Coal- Coal is a sedimentary rock found deep in the earth. It is composed mainly of carbon, hydrogen, and oxygen. It forms from buildup of organic matter, found along the edges of shallow seas, lakes, or rivers. Flat swampy areas that are episodically flooded are the best candidates for coal formation. http://www.worldcoal.org/coal/
8. Mercury- the chemical formula for mercury is Hg. The color of mercury is considered a tin-white like look. Mercury occurs as small liquid blobs above in the crevices of mercury ores. Mercury is a liquid and turns into a solid so it does not have a crystal structure.
Mineral guides such as Dana's System of Mineralogy, categorize Mercury together with the "true" minerals. The rock type of mercury is Igneous, Metamorphic. Another interesting point is when it is heated over 675 degrees Fahrenheit it volatilizes. http://www.minerals.net/mineral/mercury.aspx
9. Sulfur- Sulfur is bright yellow. The color may be altered if imperfections are present. Sulfur is soft, light in weight, and very brittle. It should be handled as little as possible, and kept out of light to avoid cracking. Every atom of sulfur has 16 protons and 16 neutrons. Sulfurs scientific name is Rosickyite. It may have a greasy feel and may dissolve in warm water. http://www.minerals.net/mineral/sulfur.aspx
10. Copper- The chemical formula of copper is Cu. It is commonly associated with iron and silver. Copper is reddish brown and can tarnish green, blue, or black. Often found as distorted masses or extremely distorted crystals. Copper is an...