Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by composition]
6. inorganic material
7. mineral

Anotations

Scope note:

A white, amorphous mineral composed of silicate, carbonate, and calcium sulfate. It is often formed by the reaction of sulfates and concrete or mortar. Thaumasite crystal formation induces sulfate decay in the cement paste matrix. Conservation interventions seek to remove thaumasite or limit its attack.