Start pounding the almonds in a marble mortar.
Gradually pound in the sugar a spoonful at a time until it is all incorporated.
Pound in the rosewater, musk, ambergris, and lemon zest until the mixture is a fine paste.
Pinch off balls and roll them in some additional sugar, then place on parchment-lined sheets. Bake in a slow oven (275–300°F/135–150°C) until dried through.