Iron-oxide concretions and nodules

Blueberry Hills: Utah nodules resemble some found on Mars

PDF) Iron-Oxide Concretions: Hallmarks of Altered Siderite Masses of Both Early and Late Diagenetic Origin

Erfoudites rherisensis (KORN, 1999)

PDF] Characterization of Navajo Sandstone concretions: Mars

Self-organized iron-oxide cementation geometry as an indicator of paleo-flows

Concretion - Wikipedia

Iron concretion hi-res stock photography and images - Alamy

AVERY GREGORY on Instagram: Iron-oxide / hematite rich stones

Anyone got a clue what this is? It was found in a field in Denmark of all places. : r/geology

What are these rocks I found in the Gobi? : r/whatsthisrock

Iron-oxide concretions and nodules

Fe-Mn concretions and nodules formation in redoximorphic soils and

NASA Astrobiology Institute

Nodules, Concretions, Other Interesting Rocks For Sale