A collection of collections and a specialization of type of temporally and spatially stuff-like thing. Instances are subcollections of tangible thing whose membership is based only on the physical and/or chemical composition of their instances. tangible stuff type does not have as instances collections whose instances are determined _solely_ by the physical state they are in -- for that, see tangible stuff state type. However, many substances that chemically break down before melting (e.g. fatty tissue) _are_ included in this collection, even though they exist solely in one physical state.

The collection water is an instance of tangible stuff type, as instances of water are all pieces of substance with the chemical composition H20. On the other hand , the collection of all pieces of ice (i.e. (solid water)) is not a tangible stuff type, because membership in that collection depends on the substance's composition _and_ on its physical state. baby powder is not an instance of this collection because a fused mass of the substance would no longer be powder, but would still be of the same tangible stuff type.

Further instances of tangible stuff type are nylon, gasoline, fatty tissue, nitrogen, and glass. An important specialization of this collection is chemical substance -- those substance types defined solely by their chemical formulae.