Corundum

Corundum is made up of aluminum oxide, iron, and titanium. It has a hardness of 9. The color of the mineral corundum is clear if no elements are added, but when added the color and vary to reddish pink, blue, purple, brown, green, and yellow. The luster of corundum is vitreous. Even though the color can vary, the streak of this mineral is white. The density of this is 3.98-4.1 g/cm3. The crystal structure is trigonal. It can be shaped like a pyramid or form into a hexagonal dagger. No cleavage, but the fracture is irregular or uneven conchoidal. The special characteristics of this mineral is that the index of corundum is around 1.77, and it is the 2nd hardest mineral in the world next to the diamond. It is formed from aluminum oxide which is common in metamorphic rocks. It is found in Burma, South Africa, the Ural Mountains in Western Russia and in the United States. Uses for corundum are in jewelry, to polish compounds, cutting tools, sandpaper, grinding, and is used lastly for windows and scanning devices for stores. It is not found in Iowa. It has been found in the Missouri river though.

Sites: [] [] []

[] [] [] [] []