Volcanoes blowing 'smoke rings' of steam and gas are not unusual, but it sure is a beautiful event.

This doesn't qualify as a "strange thing", but is sure is an awesome sight to behold :

Fire, Lava, Lightning



io9 has the explanation for this spectacular, but thoroughly, destructive display of nature :

Several days ago, a volcano that had been dormant for 9,000 years near the coast of Chile erupted spectacularly, hurling liquified metals and lightning many miles into the sky. The results, which you see here, are called a "dirty thunderstorm," and are quite rare. Nobody is certain what causes them, but according to National Geographic it's believed to be "the result of rock fragments, ash, and ice particles in the plume collid[ing] to produce static charges—just as ice particles collide to create charge in regular thunderstorms."