Each site has its own raw probabilities and its own lists of possible fragments and resources. No site provides everything.
The five Excavation resources are: Monarchic Alloy, Weave Filament, Mnemic Substrate, Pillar Ceramic, and Breach Condensate. Fragments correspond to accessories; their catalog, effects, and compatibility information are listed in Accessory Catalog.
A specialized site may favor a particular family; sites with broader lists offset this versatility with less concentrated probabilities. Site data are rolled when the universe launches and remain stable. The Excavation report lists the results obtained; the Stratigraphic Scanner can also reveal the site's raw data under the conditions described in the catalog.

