Elementary and microscopic constituent of coal. There are a number of different types. Alginite is formed from algal remains; typical of boghead coal. Collinite derives from cell infillings, is structureless and falls within the vitrinite coal-maceral group. Cutinite consists of plant cuticles, usually the hard outer coat of the epidermal cells of leaves. Fusinite comes from woody material; it has high reflectivity and microhardness (its individual grains are hard), well-defined cellular structure (Bogen structure), and is high in carbon. Micrinite has high reflectivity, medium hardness, is opaque, granular, with grain size less than 10 μ‎m, and has no cell structure. Resinite is formed of small ellipsoids or spindles of resin, a cell-infilling material. Sclerotinite describes variously sized round or oval bodies of irregular structure which may have been fungi or spores. It is similar in hardness and reflectivity to fusinite. Sporinite is formed of spore exines, usually flattened parallel to stratification. Telinite is that part of the vitrinite group deriving from cell-wall material.