Know all about Tachylite and Icelandite properties here. All properties of rocks are important as they define the type of rock and its application. Tachylite and Icelandite belong to Igneous Rocks.Texture of Tachylite is Vitreous whereas that of Icelandite is Aphanitic to Porphyritic. Tachylite appears Glassy and Icelandite appears Dull and Soft. The luster of Tachylite is resinous while that of Icelandite is vitreous. Tachylite is available in black, dark brown colors whereas Icelandite is available in bluish - grey, grey, pink, yellow colors. The commercial uses of Tachylite and Icelandite are cemetery markers, creating artwork.