You can be forgiven if you don’t know where the salt in your cupboard comes from. When you’re at the supermarket, perhaps you don’t select salt with the same care you use to select tomatoes or salmon, assessing quality, color, or responsible means of harvest and cultivation. But there was a time in our history when humans considered salt as precious as jewels and lustrous metals; when nations waged war over access to this mineral; when revolutions fomented against its taxation, and salt was reserved for communion with gods.