motl57

Wenderholm Regional Park, Southern End (-36.541774, 174.711260); East Coast, North Island, New Zealand - Loose on shoreline nearby cliff

I was thinking quartzite maybe (see first and last photo especially; the isolated crystals in photo 4 would then be quartz if its quartzite), but don't know what the covering is, nor the other layers present. Also some parts appear like small blebs (eg photo 2) and there is a green mineral present (maybe green patina copper?) (photo 3 and 7). Is rather hard (some parts don't scratch with metal, but others - back covering (eg photo 6) are softer and do scratch slightly with metal) and does not fizz in contact with mild acid (vinegar). Thanks 🙂

I think it is Botryoidal Goethite (rather than hematite) as the streak is "Yellowish brown, orange-yellow, ocher-yellow" and not "Reddish brown ('rust-red')":

Thanks for all the quick replies! This is very encouraging.

Is not crumbly and does not have any trapped air. Is very hard. I know its some kind of oxidizing iron formation, but I don't know its name. Thanks. 🙂