Know all about Chalk and Rhomb Porphyry properties here. All properties of rocks are important as they define the type of rock and its application. Chalk belongs to Sedimentary Rocks while Rhomb Porphyry belongs to Igneous Rocks.Texture of Chalk is Clastic or Non-Clastic whereas that of Rhomb Porphyry is Aphanitic to Porphyritic. Chalk appears Soft and Rhomb Porphyry appears Rough. The luster of Chalk is dull while that of Rhomb Porphyry is subvitreous to dull. Chalk is available in grey, white, yellow colors whereas Rhomb Porphyry is available in black, brown, colourless, green, grey, pink, white colors. The commercial uses of Chalk are alumina refineries, creating artwork, drawing on blackboards, gymnasts, athletes and mountain climbers use for grip, in aquifers, paper industry, production of lime, raw material for manufacture of quicklime, slaked lime, soil conditioner, whiting, whiting material in toothpaste, paint and paper and that of Rhomb Porphyry are an oil and gas reservoir, as a feed additive for livestock, metallurgical flux, soil conditioner, source of magnesia (mgo).