\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.
{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.