Diorite is a coarse-grained intrusive igneous rock with a granular texture, composed primarily of plagioclase feldspar, biotite, hornblende, and pyroxene. In 3D modeling, it should feature a speckled appearance with a mix of dark and light minerals, giving it a salt-and-pepper look. The surface should be rough and uneven, with visible crystalline structures and occasional larger mineral inclusions for authenticity.