Know all about Gneiss and Icelandite properties here. All properties of rocks are important as they define the type of rock and its application. Gneiss belongs to Metamorphic Rocks while Icelandite belongs to Igneous Rocks.Texture of Gneiss is Banded, Foliated, Platy whereas that of Icelandite is Aphanitic to Porphyritic. Gneiss appears Foliated and Icelandite appears Dull and Soft. The luster of Gneiss is dull while that of Icelandite is vitreous. Gneiss is available in black, brown, pink, red, white colors whereas Icelandite is available in bluish - grey, grey, pink, yellow colors. The commercial uses of Gneiss are cemetery markers, jewelry, tombstones, used in aquariums and that of Icelandite are cemetery markers, creating artwork.