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Sammyg
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If diamonds are made of carbon? and coal is made out carbon, why are diamonds transparent and coal is not transparent?
Sammyg said:If diamonds are made of carbon? and coal is made out carbon, why are diamonds transparent and coal is not transparent?
Bob S said:Diamond density is about 3.5 to 3.53 grams per cubic cm, while graphite is only 2.0 to 2.25 grams per cubic cm.
Diamond is one of several carbon allotropes, which include fullerenes {buckyballs), nanotubes, graphite, graphene, and coal (not really an allotrope). Graphite is a good electrical conductor, while diamond is a good insulator. Diamond is a very good thermal conductor but at the same time an electrical insulator (doesn't obey the Wiedeman Franz law). If sulfur can have red, yellow, and black allotropes, why can't carbon have one that is transparent?Vanadium 50 said:And what does that have to do with transparency?
Division said:Diamonds are carbon put into high amounts of pressure and heat.
The whole process is very expencive, too expencive for any practical use in making them. The quantity of diamond you get out of any amount of carbon is too costly to be beneficial, therefore, this process is rarely used, if ever.
Phrak said:Yes, but the industry produces in the region of 3 billion carats, or 600 metric tons of synthetic diamonds a year.
Maybe we can explain using semiconductor concept. Semiconductor has a band gap which is the difference between valence band and conduction band, and photons of larger energy than this band gap can be absorbed. In diamond the band gab is larger than visual light I think, but in silicon it is not. So silicon can be used as a infrared light pass filter blocking visual light. Coal is obviously mixture of many crystal like forms so the overall band gap is almost zero, meaning that all frequency light will be absorbed.Sammyg said:If diamonds are made of carbon? and coal is made out carbon, why are diamonds transparent and coal is not transparent?
Diamonds and coal are both forms of carbon because they are both made of the same element, carbon. However, the difference lies in the way the carbon atoms are arranged. In diamonds, the carbon atoms are arranged in a tightly bonded, crystalline structure, making it the hardest naturally occurring substance. In coal, the carbon atoms are bonded more loosely, resulting in a softer, more brittle substance.
The value of diamonds is determined by a combination of factors including rarity, durability, and demand. Diamonds are much rarer than coal, which is abundant and widely used for energy production. Additionally, the unique qualities of diamonds, such as their brilliance and hardness, make them highly sought after for use in jewelry and industrial applications.
No, the process of forming diamonds and coal is not the same. Diamonds are formed deep within the Earth's mantle under intense heat and pressure, whereas coal forms from the remains of plants and trees that were buried and subjected to heat and pressure over millions of years.
Technically, yes, coal can be turned into diamonds through a process called "synthetic diamond production." This involves subjecting coal to high temperatures and pressures in a laboratory setting, mimicking the natural conditions that form diamonds. However, this process is expensive and not economically feasible on a large scale.
No, diamonds and coal are not the only forms of carbon. Graphite, for example, is also a form of carbon. It has a layered, hexagonal structure and is used in pencils and as a lubricant due to its slippery properties. Other forms of carbon include fullerenes, nanotubes, and graphene, which have unique properties and potential applications in various industries.