Starting 345,000,000 years ago, swamps formed and sea sediments covered them hundreds of times, making many rock and dead-plant layers. Layer weight created high pressure that changed organic matter into carbon forms {carbon mineral}.
types
Under pressure, organic matter turns slowly into first peat, then lignite, then bituminous coal, and then anthracite coal, as it becomes more crystalline.
coal
Many places that used to be under sea have coal, such as USA, Canada, England, and Russia.
petroleum
Decaying organic matter trapped in anti-clinal deposits became petroleum, with natural gas above it, as in Saudi Arabia, Middle East, and Russia.
diamond
Diamonds are covalently bound pure carbon and form at 5000 F and 1,000,000 lb/in^2 pressure, 240 miles below surface. Almost all diamonds are in South Africa. Diamond size is by weight {carat}.
graphite
Graphite is soft carbon. Hexagon graphite layers include heptagons, resulting in negative curvature. Hexagon graphite layers include pentagons, resulting in positive curvature.
Pure carbon can be amorphous {amorphous carbon}, with diamond bonds and graphite bonds.
Pure carbon can form into balls {buckyball} {buckminsterfullerene} with five-carbon and six-carbon rings, like soccer ball hexagons and pentagons.
Pure carbon can form low-density gel {carbon aerogel}.
Yams, soybeans, and tropical plants have lower carbon-13 to carbon-12 ratio than temperate-zone plants {carbon isotope ratio test} (CIR).
Pure graphite hit by meteorites forms hexagonal structure {chaoite}.
Pure carbon fibers can have small plates in chains {filamentous carbon}.
Pure carbon {graphene} can form plane hexagonal arrays. Array is flexible but stronger than diamond. Graphene has strong bonds and flexibility and so rarely has missing atoms or impurities. Graphene conducts electricity fastest, because bonds are strong and crystal defects are few. Charge carriers move at 1/300 light speed and have relativistic effects.
Pure carbon can form hexagonal-pattern diamonds {lonsdaleite} {hexagonal diamond}.
Pure carbon can form aerogel-like structure {nanofoam} that is ferromagnetic.
Pure carbon can make material {nanorod} harder than diamond.
Pure carbon can form into six-carbon-ring tubes {buckytube} {nanotube, carbon}, 10 or more carbons diameter, 10000 carbons long, strong, heat-resistant, radiation-resistant, resilient, flexible, conducting or semiconducting, and nested or single (Sumio Iijima) [1991]. Random nanotubes arrangements {nanonet} conduct electricity.
Pure carbon can form hexagonal structure {schwartzite} with included heptagons.
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Date Modified: 2022.0225