Basal

Basalt - is most widespread aya the streamed volcanic breed. These are dense breeds (density 2,75-3,1), is more rare with porous structure. Color of material can be generally light-/tyomno-s ardent and black, but on certain fields also pink. Basalts from the top parts of streams of a lava can be porous as when hardening hot weight, from it gases and vapors were emitted. Subsequently in the formed time other minerals - zeolite, calcite, native copper were postponed, prenit, quartz, etc.