Moon Rocks are Items exclusive to Don't Starve Together. They are obtained by mining crash-landed Meteors, which have the appearance of sharp rocks striped with jagged blue cracks. Moon Rocks can be crafted into Walls, Cratered Moonrocks and Moon Dials.
Meteor Boulders will only land in areas surrounded by other Boulders, such as Rockyland Biomes. The meteors that Moon Rocks are mined from cannot be seen falling from the sky, but they do cast large shadows right before landing. Mining a meteor will yield 2 Rocks, 1 Flint, and 1 Moon Rock. There is a 25% chance to get an extra Moon Rock and a 60% chance for an extra Flint.