minecraft-assets/assets/minecraft/models/item/bone.json

{
    "parent": "item/handheld",
    "textures": {
        "layer0": "item/bone"
    },
    "display": {
        "head": {
            "rotation": [ 0, 0, -45 ],
            "translation": [ 0, -4.5, -6.5],
            "scale":[ 1, 1, 1 ]
        }
    }
}