Know all about Tonalite and Tachylite properties here. All properties of rocks are important as they define the type of rock and its application. Tonalite and Tachylite belong to Igneous Rocks.Texture of Tonalite is Phaneritic whereas that of Tachylite is Vitreous. Tonalite appears Banded and Foilated and Tachylite appears Glassy. The luster of Tonalite is subvitreous to dull while that of Tachylite is resinous. Tonalite is available in black, brown, light to dark grey, white colors whereas Tachylite is available in black, dark brown colors. The commercial uses of Tonalite and Tachylite are cemetery markers, creating artwork.