Shatter is a type of cannabis extract that resembles a thin, translucent, glass-like piece of wax.  The extraction process can include a variety of solvents like butane, ethanol, and others.  Shatter is traditionally made from dried cannabis material and is a combination of terpenes, cannabinoids, and other chemical components.  In good condition, this will make a snap sound when breaking off a piece, but with exposure to heat and other elements, may become runny and sappy.