MINERALS AND OTHER MATERIALS

Precious metals defined:
Gold, silver and platinum as defined by law and its intrinsic value.

How much wood is used to make a ton of paper?
2 cords of wood, as well as, 55,000 gallons of water, 102 pounds of sulfur, 350 pounds of lime, 289 pounds of clay, 1.2 tons of coal, 112 kilowatt hours of power, 20 pounds of dye and pigments, and 108 pounds of starch, as well as other ingredients.

Petrified wood defined:
Water containing dissolved minerals such as calcium carbonate (CaCO3) and silicate infiltrates the wood, and the minerals gradually replace the organic matter. The process takes thousands of years. The wood itself does not turn to stone.

Luffa sponge defined:
Luffas are nonwoody vines of the cucumber. The interior fibrous skeletons of the fruit are used as sponges.

Glass defined:
At room temperature, glass appears to be a solid in the ordinary sense of the word. However, it actually is a fluid with an extremely high viscosity.