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