Basalt is a natural material that is found in volcanic rocks. It is mainly used (as crushed rock) in construction, industrial and high way engineering. One can also melt basalt (1300-1700°C) and spin it into fine fibers. Some possible applications of basalt fibers and basalt-based composites are: thermal and sound insulation/protection (e.g. basalt wool, engine insulation), pipes, bars, fittings, fabrics, structural plastics, automotive parts, concrete reinforcement (constructions), insulating plastics and frictional materials. Mechanical properties E-glass: 3.4±0.7 GPa for fibers and 0.86-1.27 GPa for rovings Basalt : 1.43±0.59 GPa for fibers and 0.69–0.92 GPa for rovings (density: 2.6-2.8 g/cm³) Basalt also has a higher modulus (82-110 GPa) than E-glass (68-73 GPa). Thermal properties Basalt can be used over a wide temperature range, from about -260/-200 to about 650/800°C Chemical properties Basalts are more stable in strong alkalis than glass, while they are slightly less stable in strong acids