The Collaborative International Dictionary
Siliceous sinter
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.
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.