The mineral afwillite (3CaO.2SiO2.3H2O) is so far recorded only from the Kimberley Mines (Parry and Wright, Min. Mag., 1925, p. 277), where it occurs in association with natrolite, apophyllite, and calcite in a dolerite inclusion in kimberlite. Its occurrence with markedly different associations is sufficient warrant for a short record. Examination of the mineral associates of spurrite of the contact zone of the Scawt Hill dolerite Co. Antrim has revealed a second occurrence of afwillite, lining a cavity in a thin calcitic crust covering a spurrite contact rock.