At 563 carats, the Star of India is the world’s largest gem-quality blue star sapphire, and is approximately 2 billion years old. (Image credit: D. Finnin/Copyright AMNH) ================================================================== What does the legendary Star of India — a 563-carat star sapphire the size of a golf ball — have in common with a 35-million-year-old petrified redwood slab; a massive cluster of sword-like crystals that looks like it came from "Game of Thrones;" and a 5-ton (4.5-metric ton) stone pillar that can "sing?" You can see all of them, along with 5,000 other amazing stones, in the newly renovated Mignone Hall of...