minecraft-assets/assets/minecraft/blockstates/purple_concrete_powder.json

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