tautoclinMin.|ˈtɔːtəʊklɪn| [ad.Ger.tautoklin (Breithaupt 1830), f.Gr. ταὐτό (tauto-) + κλίνειν to bend, incline; so called ‘because it has the same rhombohedral angle as dolomite’ (Chester).] A greyish-white variety of ankerite. 1868Dana Min. (ed. 5) 685.