Motukoreaite occurs as claylike cement or hexagonal tabular crystals up to 0.2 mm (0.0079 in) in size that form rosettes, boxworks, and subparallel aggregates.

[2] Motukoreaite has been found in association with apatite, barite, calcite, chabazite, calcic plagioclase, gismondine, gypsum, hisingerite, hydrotalcite, limonite, magnetite, montmorillonite, nordstrandite, olivine, phillipsite, pyroxene, quartz, and zeolites.

The mineral's small crystal size made determination of its optical properties difficult.

[9] Motukoreaite is known from Motukorea, New Zealand, La Piatta quarry in Italy, Stradner Kogel in Austria,[3] and the western Mediterranean Sea near Spain.

[2] The type material is held at the University of Auckland in Auckland, New Zealand, the Natural History Museum, London, and the National Museum of Natural History in Washington, D.C.[2] Media related to Motukoreaite at Wikimedia Commons