Properties of Obsidian lan Anthracite
ukuran gandum
ora ditrapake
medium kanggo nggoleki coarse grained
rengat
conchoidal
conchoidal
porosity
banget kurang keropos
kurang keropos
kekuatan compressive
ora Sumadhiya
kateguhan
ora kasedhiya
ora kasedhiya
tartamtu gravitasi
2.6-2.7
1.1-1.4
Kapadhetan
2.6 g / cm 3
1.25-2.5 g / cm 3
resistance
tahan panas, impact tahan
tahan panas, banyu tahan