Inertinite is oxidized organic material or

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

ized

charcoal Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, cal ...

. It is found as tiny flakes within

sedimentary rock Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name for processes that cause these particles ...

s. The presence of inertinite is significant in the geological record, as it signifies that

wildfire A wildfire, forest fire, bushfire, wildland fire or rural fire is an unplanned, uncontrolled and unpredictable fire in an area of Combustibility and flammability, combustible vegetation. Depending on the type of vegetation present, a wildfire ...

s occurred at the time that the host

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand an ...

was deposited. It is also an indication of oxidation due to atmospheric exposure or fungal decomposition during deposition. Inertinite is a common

maceral A maceral is a component, organic in origin, of coal or oil shale. The term 'maceral' in reference to coal is analogous to the use of the term 'mineral' in reference to igneous or metamorphic rocks. Examples of macerals are inertinite, vitrinite, ...

in most types of

coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when dea ...

. The main inertinite submacerals are

fusinite Fusain is a fossilised carbon deposit which, after some controversy, has been identified as fossilised charcoal. It is fibrous, black and opaque, and often preserves details of cell wall architecture. Wood-derived fusain usually takes the form ...

, semifusinite,

micrinite Inertinite is oxidized organic material or fossilized charcoal. It is found as tiny flakes within sedimentary rocks. The presence of inertinite is significant in the geological record, as it signifies that wildfires occurred at the time that the ho ...

, macrinite and

funginite Funginite is a maceral, a component, organic in origin, of coal or oil shale, that exhibits several different physical properties and characteristics under particular conditions, and its dimensions are based upon its source and place of discovery. ...

. The most common type of inertinite maceral is semifusinite. The optical properties of semifusinite are very similar to those of

vitrinite Vitrinite is one of the primary components of coals and most sedimentary kerogens. Vitrinite is a type of maceral, where "macerals" are organic components of coal analogous to the "minerals" of rocks. Vitrinite has a shiny appearance resembling gla ...

. They differ in that semifusinite displays a folded texture as compared to vitrinite which generally maintains its composed structure. Inertinites also displays higher

reflectance The reflectance of the surface of a material is its effectiveness in reflecting radiant energy. It is the fraction of incident electromagnetic power that is reflected at the boundary. Reflectance is a component of the response of the electronic ...

than vitrinite, except when approaching an anthracitic or

graphite Graphite () is a crystalline form of the element carbon. It consists of stacked layers of graphene. Graphite occurs naturally and is the most stable form of carbon under standard conditions. Synthetic and natural graphite are consumed on large ...

state.

References

Sedimentary rocks {{petrology-stub