Copper

https://www.linkedin.com/posts/activity-6894738473044299776-xUyP - Artistic visualisation of the volume of refined #copper extracted during the lifetime at Palabora, South Africa’s largest copper mine. The metal bubble is a refined copper equivalent for 4.1 million tonnes of copper concentrate extracted

The artwork is titled “For what it's worth” - http://dillonmarsh.com/fwiw.html by Dillon Marsh