Which is the most stable allotrope of carbon?

The most stable allotrope of carbon is graphite, under standard temperature and pressure (STP). Graphite hasa covalent bond, an sp2 hybridization, which is actually stable. Electrons delocalize in graphite, and this makes it more stable. The electrons have freedom of movement, and thus making graphite to be a good conductor of electricity. It basically conducts electricity along the carbon atoms plane but refuses to conduct at a right angle degree to the plane.

In thermochemistry, it is used as the standard or basic state for determining heat formation in compounds of carbon. Graphite does not burn when subjected to high heating, or at high temperature. Because of this property it possesses, it is used for high-temperature crucibles and in nuclear reactors for melting metals. The powder from graphite is used as a dry lubricant. Graphite can as well be transformed into diamond at very high pressures and temperatures.

Surprisingly, graphite is the most stable of all the allotropes in regular conditions that carbon comprises. Diamonds run a close second, but graphite is more stable, allowing more refinement and because it is a poor conduit for heat, it allows for more uses in items such as heaters, batteries, and many other electrical products.

It is usually found in a hexagon shape, and occur this way naturally. When it is discovered in this natural state, it is one of the best forms of carbon to work with. The covalent bonds of graphite are only comprised of three bonds, so the ease of working with it make it more stable.

If you were to put the graphite through extreme heat and pressure, it would eventually convert to a diamond state. This process is used by some diamond manufacturers to replenish and maintain stores for drill bits, and the many other uses that diamonds fall into.