Optical Calcite: A glass block with birefringence

Since Calcite is already in the game but has limited uses, we should be able to craft "Optical Calcite" (Iceland Spar) by combining Calcite with Amethyst Shards or Quartz. When placed, Optical Calcite behaves like a special type of glass. Looking through it triggers a unique "birefringence" shader effect, making everything on the other side appear duplicated or shifted. Gameplay Uses: • Optical Glass: Perfect for creating optical illusions, confusing mazes, and secret bases where players can't easily see where a button or lever actually is. • Sunstone (Navigation Tool): Just like the Vikings used it in real life, players could hold it in their hand on cloudy days or during storms in the ocean to reveal the exact position of the Sun or Moon through the clouds. • New Redstone/Spyglass Component: It could be used to craft an upgraded Spyglass or a redstone sensor that splits light paths. This would give Calcite a unique, mind-bending utility that fits perfectly with Minecraft’s sandbox nature!