Inorganic compound

In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds⁠‍—‍that is, a compound that is not an organic compound.^[1]^[2] The study of inorganic compounds is a subfield of chemistry known as inorganic chemistry.

Inorganic compounds comprise most of the Earth's crust, although the compositions of the deep mantle remain active areas of investigation.^[3]

All allotropes (structurally different pure forms of an element) and some simple carbon compounds are often considered inorganic. Examples include the allotropes of carbon (graphite, diamond, buckminsterfullerene, graphene, etc.), carbon monoxide CO, carbon dioxide CO₂, carbides, and salts of inorganic anions such as carbonates, cyanides, cyanates, thiocyanates, isothiocyanates, phosphates, sulphates, chlorates, etc. Many of these are normal parts of mostly organic systems, including organisms; describing a chemical as inorganic does not necessarily mean that it cannot occur within living things.

^ J. J. Berzelius "Lehrbuch der Chemie," 1st ed., Arnoldischen Buchhandlung, Dresden and Leipzig, 1827. ISBN 1-148-99953-1. Brief English commentary in English can be found in Bent Soren Jorgensen "More on Berzelius and the vital force" J. Chem. Educ., 1965, vol. 42, p 394. doi:10.1021/ed042p394
^ Dan Berger, Bluffton College, analysis of varying inappropriate definitions of the inorganic-organic distinction: Otherwise consistent linked material differing from current article in downplaying the carbon present vs carbon absent distinctive: [1]
^ Newman, D. K.; Banfield, J. F. (2002). "Geomicrobiology: How Molecular-Scale Interactions Underpin Biogeochemical Systems". Science. 296 (5570): 1071–1077. Bibcode:2002Sci...296.1071N. doi:10.1126/science.1010716. PMID 12004119. S2CID 1235688.