Sinter \Sin"ter\, n. [G. Cf. {Cinder}.] (Min.) Dross, as of iron; the scale which files from iron when hammered; -- applied as a name to various minerals. [1913 Webster] {Calcareous sinter}, a loose banded variety of calcite formed by deposition from lime-bearing waters; calcareous tufa; travertine. {Ceraunian sinter}, fulgurite. {Siliceous sinter}, a light cellular or fibrous opal; especially, geyserite (see {Geyserite}). It has often a pearly luster, and is then called pearl sinter. [1913 Webster]