Ruby Coaster

prusaprinters

<p>If you're going to make a coaster out of ruby, then it should be real ruby!</p><p>Each 8-sided polygon is an octahedron containing an Al atom. &nbsp;Each corner of each octahedron has an oxygen atom – and some corners are shared by multiple octahedra. &nbsp;This makes corundum which is clear and colorless. &nbsp;By replacing about 1 out of every hundred Al atoms with a Cr atom the crystal turns red and is called ruby. &nbsp;Sapphire can also be created by replacing some of the Al with Ti or Fe.</p><p>The crystal structure was created using CrystalMaker and then edited using Blender.</p>