The Kristall Galerie houses the largest known crystal cluster in the world.

The quartz crystals from Otjua are perfect and beautiful crystals. They are furthermore unique since many of them are doubly terminated, thus identifying them as "floaters", i.e. they grey while floating in the mineralized fluid, rather than growing onto a surface. There is no record in literature for the largest "floater" ever found, and it might well be that Otjua crystal do have distinction of being the largest. The largest single crystal from Otjua ia a floater with a length of 2.2 m and a circumference of 1.8 m. It has a estimated weight of 1 ton and is part of a cluster displayed in the foyer if Kristall Galerie  in swakopmund.