Suspicious sand and suspicious gravel are fragile gravity-affected blocks found in various Overworld structures. They can be brushed to extract structure-dependent loot, and are the only source of pottery sherds. Suspicious blocks drop nothing if they are broken, and break if they fall from any height or are moved with a piston. They are rare to find. Suspicious blocks are unobtainable by mining, even using a tool enchanted with Silk Touch. They are much softer than normal sand and gravel...