Know all about Rhomb Porphyry and Gneiss properties here. All properties of rocks are important as they define the type of rock and its application. Rhomb Porphyry belongs to Igneous Rocks while Gneiss belongs to Metamorphic Rocks.Texture of Rhomb Porphyry is Aphanitic to Porphyritic whereas that of Gneiss is Banded, Foliated, Platy. Rhomb Porphyry appears Rough and Gneiss appears Foliated. The luster of Rhomb Porphyry is subvitreous to dull while that of Gneiss is dull. Rhomb Porphyry is available in black, brown, colourless, green, grey, pink, white colors whereas Gneiss is available in black, brown, pink, red, white colors. The commercial uses of Rhomb Porphyry are an oil and gas reservoir, as a feed additive for livestock, metallurgical flux, soil conditioner, source of magnesia (mgo) and that of Gneiss are cemetery markers, jewelry, tombstones, used in aquariums.