Properties used to identify igneous rocks include mineral composition, texture, and color. There are four different mineral compositions; Felsic, Intermediate, Mafic, and Ultramafic. The texture of an igneous rock is determined by its grain size.ince the cooling process is very slow intrusive igneous rocks have very large crystals (coarse grained). In some instances there is also a third type of igneous rock. Technically it is an extrusive rock, but it resembles glass. This glass type of igneous rock forms when magma/lava is instantly cooled.