4 ms·Metal and hard rock are essential for life.by GuB-42 1y agoMetal and hard rock are essential for life.labster 1y agoI think they were referring to metals like carbon and oxygen, but I’m sure Led Zeppelin is important too.1-more 1y agoCarbon and Oxygen are not metals though, right?hollerith 1y agoAccording to the definition used by astronomers, all elements heavier than hydrogen and helium are metals.1-more 1y agofascinating!!GuB-42 1y agoA good reason for recycling centers to hate astronomers.Towaway69 1y agoAs Douglas Adams wrote, life is about banging the rocks together.