Hardest Mineral
What do a glittering diamond and a lead pencil have in common? Diamonds are very hard and the graphite of the pencil’s tip is very soft. These two different substances contain a wonderful proof of creation called carbon.A rough, unpolished diamond is the hardest of all minerals. For this reason, a crystal diamond is used to cut and to drill all kinds of material and is also used as an abrasive to smooth surfaces.
Hardness is the resistance of a mineral to scratches from outside forces; it is easy to recognize minerals by this trait. By scratching one mineral with another, their relative hardness can be determined. Diamond has an extremely low thermal expansion, is chemically inert with respect to most acids and alkalis, is transparent from the far infrared through the deep ultraviolet, and is one of only a few materials with a negative work function (electron affinity).
One consequence of the negative electron affinity is that diamonds repel water, but readily accept hydrocarbons such as wax or grease. Diamonds do not conduct electricity well, although some are semiconductors. Diamond can burn if subjected to a high temperature in the presence of oxygen. Diamond has a high specific gravity; it is amazingly dense given the low atomic weight of carbon. The brilliance and fire of a diamond are due to its high dispersion and high refractive index. Diamond has the highest reflectance and index of refraction of any transparent substances. Diamond gemstones are commonly clear or pale blue, but colored diamonds, called ‘fancies’, have been found in all the colors of the rainbow.
Tags: diamonds
Related Posts
- How To Choose A Good Vitamin Supplement
- Zeolite - Just A Fad, Or Can It Really Change Your Life?
- Improve Speaking Skills
- The In Depth Study Of Mesothelioma Part 2 - Peritoneal Mesothelioma
- Symptons Of Testicular Cancer - Testicular Cancer Warning Signs To Watch For