The affinities of L. coleorum are still unclear. The nearest match for its seeds and fruits is found in L. werneri. If these taxa are closely related, this suggests a very large disjunction, some 1300 kilometres. However, L. werneri consistently shows the fine red markings ('rubri-cations' sensu Cole) characteristic of its Namibian neighbours, L. pseudotruncatella (Berger) N.E.Br, and L. gracilidelineata Dinter, whereas L. coleorum lacks them. Also, the three Namibian species have a characteristically slow maturation, retaining a short juvenile fissure for several years. Other possible relatives - L. gesineae De Boer from the Tiras Mountains in central Namibia, and L. terricolor (N.E.Br.) N.E.Br, from the western Cape (both taxa lack rubrications and have a window structure roughly comparable to that of L. coleorum) - would still present very large disjunctions, otherwise unknown in Lithops.
Plant dwarf, solitary or forming clusters of 2-4 (rarely 7-8) bodies. Sheath pale brown, spotted with darker tannins, completely enclosing the resting bodies in winter but disintegrating quickly by the subsequent autumn. Roots lateral, rather short, not forming a deep taproot, dark brown. Bodies obcordate in outline, usually strongly convex above, up to 40 mm tall x 15 mm broad (transverse to the fissure) x 10 mm thick, but usually much smaller: 15-20 x 10-15 x 6-10 mm; fissure extending across the whole width, lobes conjunct, ± equal, shoulders rounded. Apex and sides pale creamy brown, often suffused with pink or green, smooth but not glossy. Window expressed as wide or narrow non-impressed translucent zones with numerous scattered blackish or greenish tanniniferous idioblasts 0.5-1 mm in diam., rubrications entirely absent. Flowers appearing in early autumn, opening in the late afternoon, short-lived, faintly scented. Peduncle 5-10 mm long, 2-3 mm thick; sepals 5, 4-6 mm long x 2 mm wide, oblong, slightly succulent, pale brown with fine reddish dots. Petals ca. 35 in 2-3 loose series, 5-10 mm long x 0.5-1.5 mm wide, ± linear with rounded apices, recurved, bright golden yellow; stamens ca. 60, filaments 4-5 mm long, papillate at the base, anthers yellow. Receptacle usually concealed within the fissure zone, elliptic as seen from above (ca. 4 x 3 mm), nectarium finely crenulate (ca. 25 divisions), dark green, stigmas 5, pale yellowish-green, equalling the anthers. Fruits concealed within the sheath until early spring, pale buff, fragile, non-persistent (or eaten?); rotund below, flat above and strongly bulging on the sides. Seeds 0.65 mm long, pyriform, pale brown, testa colliculate, 'hillocks' rougher and more numerous near the hilum. Cotyledons obconical, bright green, comparatively robust, thickening rapidly and turning brownish-green, fissure appearing as a small central pit. Seedlings maturing rapidly, often within one year.