In 1955, the Aurora Borealis, a coating applied to crystal stones to produce a "rainbow of colors" effect was introduced.
Aurora Borealis crystals remind people of the natural phenomenon
( z1 remind :ARG0 ( z2 crystal :name ( z3 name :op "Aurora" :op "Borealis" ) ) :ARG1 ( z4 phenomenon :ARG1-of ( z5 natural ) ) :ARG2 ( z6 person ) )