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. rock (inorganic material)
8. metamorphic rock
9. marble (rock)
10. [marble by form or function]
11. shell marble

Anotations

Scope note:

A shell marble which is usually either light purple or reddish brown in color. Its name means 'peacock's eye' in Italian, the eye referring to the presence of petrified oyster shells. There are two columns made of this marble in the Vatican Library.