Battle-scarred Jumbo d20
From the manufacturer:
First available through Kickstarter, we're excited to launch a full retail production run of our Battle-scarred jumbo d20s. Each die measures 25mm flat to flat and is painstakingly designed to mimic the mysterious and magical stone die from the Dice Wars: Heroes of Polyhedra logo. Designed to look like ancient magic stones, these giant dice make rolls feel like a significant event, but you can use them for just about anything else a d20 is good for.