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Cores recovered during the International Continental Scientific Drilling Program project "Drilling into Seismogenic zones of M2.0 to M5.5 earthquakes in deep South African Gold Mines" include fault breccia from within the aftershock cloud of the 2014 Orkney earthquake (M5.5). The breccia and surrounding intrusive rocks, probably lamprophyres rich in talc, biotite, calcite, and amphibole, had high magnetic susceptibilities owing to the presence of magnetite. All of these characteristics can be attributed to fluid‐related alteration. Both the breccia and the lamprophyres had low friction coefficients and showed evidence of velocity strengthening, which is inconsistent with the occurrence of earthquakes. Variable amounts of talc, biotite, calcite, and amphibole within the lamprophyres might have produced complex frictional properties and spatial heterogeneity of fault stability. The altered lamprophyres may be the host rocks of the 2014 Orkney earthquake, but frictional complexity may have governed the magnitudes of the main‐ and aftershocks and their distributions. Plain Language Summary: Drilling into seismogenic zones is an important scientific endeavor, not only to advance our understanding of the mechanisms of earthquakes, but also to provide information that will improve the resilience of humankind to these deadly hazards. The International Continental Scientific Drilling Program supported deep drilling into the aftershock region of the 2014 Orkney earthquake (M5.5) and successfully recovered samples of faulted rock material from about 3.3 km depth by drilling from a depth of about 3 km in a South African gold mine. The samples were intensively sheared and rich in talc, which is a weak mineral with a very low friction coefficient. The fault zone probably developed within this talc‐rich rock, which would indicate that the earthquake was closely related to a pre‐existing weak geological structure. However, other minerals in the fault rocks might also have influenced the spatial heterogeneity of fault stability and earthquake generation. Key Points: Fault breccia was recovered from within the aftershock cloud of the 2014 Orkney earthquake (M5.5)The fault breccia and surrounding altered lamprophyres had high talc contents and low friction coefficientsVariable amounts of talc, biotite, calcite, and amphibole might have produced complex friction properties in the lamprophyres [ABSTRACT FROM AUTHOR]