A Storm is Brewing. Lightning Strikes Again. Mercer Abrasives has added to the existing Black Lightning line with Blue Lightning and Silver Lightning. Blue Lightning is a collection of 34 diamond blades and 4 diamond cup wheels. It features an exclusive mix of industrial quality diamonds and metal powders, creating a long lasting diamond blade. Hot pressed technology produces a consistent density of segments and rims that hold up to the toughest applications. Their high diamond concentration allows the blade to last longer and increase efficiency.