The phrase "a common substance" is correct and usable in written English.
It can be used to refer to a material or chemical that is frequently encountered or widely used in various contexts.
Example: "Water is a common substance found in nature, essential for all forms of life."
Alternatives: "a widely used material" or "a frequently encountered compound."
The philosopher's stone, variously described, was sometimes said to be a common substance, found everywhere but unrecognized and unappreciated.
But the assumption that, if two articles are priced in the same currency, they must contain quantities of a common substance is gratuitous.
Water is a common substance, so the fact that it exists on Mars is not, despite some hysterical newspaper headlines, surprising.
Their involvement with the problems they share with their neighbours, near and far, has given their art a common shape and often a common substance.
Silver is a common substance used by the Mexican people for disinfecting foods and water for their consumption.
For instance, we cannot say that two molecules are identical (i.e., similarity of 1) if they generate one common metabolite but differ in the remaining molecular scaffold or two chemical mixtures are similar as they share a common substance but their formulations are basically different.
Ammonium nitrate is a fairly common substance used in such devices, and there is no evidence that the attack last Friday was inspired by or designed to mimic the Oklahoma City attack.
Zinc is a very common substance that occurs naturally.
Copper is a very common substance that occurs naturally in the environment and spreads through the environment in a natural way.
Now chemist Paul Chirik, Princeton's Edwards S. Sanford Professor of Chemistry, and his research team have found that they can replace platinum with a much more common substance — iron.
The latent heat of vaporization of water is the highest of all common substances.
