minecraft-assets/assets/minecraft/blockstates/sand.json

{
  "variants": {
    "": [
      {
        "model": "minecraft:block/sand"
      },
      {
        "y": 90,
        "model": "minecraft:block/sand"
      },
      {
        "y": 180,
        "model": "minecraft:block/sand"
      },
      {
        "y": 270,
        "model": "minecraft:block/sand"
      }
    ]
  }
}