Rubies and Implants

<p>Fascinating alumina.- The alumina family.- Polymorphs and their amazing effects.- The inside of alumina.- A little excursion into etymology.- How were rubies and sapphires determined in the past?.- How are rubies and sapphires determined today?.- Corundum - the natural aluminum oxide.- How hard is corundum?.- Ruby - the red corundum.- Sapphire - the blue corundum.- Why is ruby red and sapphire blue?.- Why are only a few rubies and sapphires found?.- In a ruby factory.- Ruby and the history of lasers.- Rubies, sapphires and watches.- Sapphire in technology.-Alumina - the artificial alumina.- Bauxite and the way to artificial alumina.- The Bayer process - from bauxite to aluminum hydroxide.- The forgotten inventor.- Calcination - from aluminum hydroxide to aluminum oxide.- The world of ceramics.- Useful sintering technology.- Is alumina ceramics resilient?.- Advantages of alumina ceramics.- The ceramic all-rounder.- Hidden in a scanning electron microscope.- Even better in a composite.- Implants and no more hip joint complaints.- News from alumina.</p><p><br></p><p>Translated with www.DeepL.com/Translator (free version)</p>