Rubble (field stone) or semi dressed stone [STRUB] - jcgomezz/Building_taxonomy GitHub Wiki

Rubble/field stone masonry is composed of uncoursed rounded field stones or roughly-cut stones used for construction with or without mortar. There are two wall wythes and a core, usually filled with stone rubble and mud. Semi-dressed stone masonry is characterized by one wall wythe (usually exterior) built using shaped stones; usually only the exposed stone surface is shaped. In some cases, stone masonry can be reinforced, usually with wood elements (wood-reinforced).

Rubble stone masonry, Italy (T. Schacher)

Rubble stone masonry constructed using round river stones in lime or cement:lime mortar, usually 250 mm thick, West Sumatra, Indonesia (J. Bothara)

Random rubble stone masonry, Cambridge, United Kingdom (S. Brzev)

Stone masonry building in Algiers suffered damage in the 2003 Boumerdes, Algeria earthquake (M. Farsi)

Rubble stone masonry with timber bands, NWFP, Pakistan (J. Bothara)

Rubble stone masonry, Maharashtra, India (S. Brzev)

Semi-dressed stone masonry, Maharashtra, India (S. Brzev)

Semi-dressed stone masonry in mud mortar, Chile (S. Mihaldzic)

Rubble stone masonry, Marrakesh, Morocco (C. Scawthorn)